Add support for converting pages from Windows encoding to Unicode

Modify method IsPlanar of BRepOffset_MakeOffset: try to make planar all possible faces to simplify the input shape.

BOPAlgo_PaveFiller_6.cxx: protection against creation of thin faces is added
bug29580_1: reverting in original state

dimensions.tcl: correction according to current state of BO algorithm

Added Qt sample OCCTOverview providing examples of use of OCCT API with relevant code and demonstration of results in the viewer.

Off-topic: some unused images are removed from dox/introduction/images/

Some variables that remain uninitialized in the project TKFillet received proper initializers.

Correction for case invalid color definition to avoid considering an entity that has a number corresponding to the color field as erroneous if entity is not a color entity.

Field theflags in class Interface_BitMap is always initialized to avoid exception on operations with the class.

Added test bugs step bug30378

Added missing puts to "test" command.

References to Flex and Bison added

Related:
- table of third-party tools in Requirements section is reorganized to be more clear
- sections Acknowledgements and Installation are updated

Definition of Poise unit corrected.

Added test bugs fclasses bug30800

- Added possibility to send stream information and transient object into Message_Messenger. Message_Printer will process it if needed.
- Add Message_PrinterToReport to send messenger information into Message_Report.
- Extended Message_Report to collect hierarchical alerts, to be able to collect some metrics during alerts processing.
- Added Message_AlertExtended to prepare hierarchical alerts with custom attributes. One attribute for one alert.
- Added Message_CompositeAlerts class to handle a container of alerts.
- Added Message_Level to start a new hierarchical level by creating an instance, stop by destricting.
- Added Message_Attribute and inheritors to store custom information about alert like object, stream, shape, some metrics.
- Implement Message_AttributeAlert to collect start/stop information about active metrics of Message_Report. This kind of attribute is created if at least one metric is active in the report.
- Add Message_MetricType enumeration with possible kinds of metrics in report.
- Implement DumpJson for Message_Report to store all collected alerts into stream.
- Added draw commands for Message_Report, Message_Messenger.

0031816: Data Exchange - RWMesh_MaterialMap::CopyTexture() copies glb file instead of a texture inside it

Image_Texture is now checked if it defines an additional offset within the file
to avoided copying an old glb file with embedded image files instead of extracting them.

Revision of User Guides

- Changes in User Guides Section to correspond with OCCT Overview structure: Mesh became a direct subsection of User Guides (it was a part of Modeling Algorithms).
  TObj is included into OCAF.
- Changes in User Guides – Modeling Algorithms section: Fillets and Chamfers, Offsets, Drafts, Pipes and Evolved shapes, Sewing, Features, 3D Model Defeaturing, 3D Model Periodicity,
  Object Modification are moved into The Topology API section.
- Changes in User Guides – Modeling Data section: Naming shapes, sub-shapes, their orientation and state section is renamed to Shape content. Shape Location is moved into Shape content section.
  Storage of Shapes is moved into BRep Format section of Specification. Lists and Maps of Shapes subsection is moved into Topology - Exploration of Topological Data Structures.
- Some pictures in User Guides (Foundation Classes, Modeling Data, Modeling Algorithms) and Tutorial are updated to improve quality and correct mistakes.

Revision of Introduction, Overview, Samples, Tutorial

- Technical Overview is incorporated into Introduction
- Samples (from Overview) and Tutorial are moved into new section Tutorials and Samples
- Content of Getting Started section (Draw Test Harness and Experimenting with Draw Test Harness) is moved into Tutorial and Samples section.
- Content changes: links to Open Cascade website promoting paid training and support are deleted.
- Some pictures in User Guides (Foundation Classes, Modeling Data, Modeling Algorithms) and Tutorial are updated to improve quality and correct mistakes.

Revised documentation of building OCCT and third-parties; some related tags updated

Move documents describing BREP format, Boolean operations, and PBR math to dox/specification

Move guides on documentation, tests, coding rules, contribution workflow to dox/contribution

Move debug and upgrade user guides to corresponding folders on upper level

Related: remove "debug" pattern from .gitignore to avoid ignoring relevant folder in dox

Move / rename overview to introduction

References have been added.

0031813: Data Exchange, RWGltf_GltfJsonParser - debug assertion in progress scope on reading glTF1.0 files

RWGltf_GltfJsonParser::gltfParseSceneNode() - removed redundant progress indication on sub-meshes list level.

- StdPrs_BRepFont inherits Standard_Transient;
- StdPrs_BRepFont contains Font_FTFont in internal field;
- StdPrs_BRepFont implements FindAndCreate;

0031762: Visualization, Font_TextFormatter - tabulation length is respected with one extra symbol shift

Integrate test case for checking various scenarios with tabulation symbol.

- Standard_EXPORT which were specified for inline methods were deleted.
- ALL occurrences of DEFINE_STANDARD_RTTI_INLINE were replaced by DEFINE_STANDARD_RTTIEXT in header files and IMPLEMENT_STANDARD_RTTIEXT in source files
- ALL occurrences of "inline" keyword were deleted where it didn't not cause a linkage errors
- Added source files for classes that were without them for IMPLEMENT_STANDARD_RTTIEXT

Added missing <stdarg.h> include (va_list) to Standard_CString.hxx.
Do not include <search.h> in delabella.cpp when using gcc 4.9 from Android NDK.

AIS_InteractiveContext::SetPickClosest() has been removed from vmanipulator command,
and test cases using the manipulator have been updated.

Detect old/new Inkscape version and pass arguments correspondingly.

- STEP low-level parser is converted to C++; required minimal version of flex is elevated to 2.5.37.
- Added possibility to import STEP from stream, see new method XSControl_Reader::ReadStream() (now implemented in STEP only).
- Parsers ported to win_flex_bison 2.5.23 (flex 2.6.4, bison 3.7.1)
- Added support of C++ flex and bison scanners in in CMake scripts
- Some code clean-up in StepFile and around (unused files and functions are eliminated)
- Option to read from stream is added in DRAW command testreadstep for testing ReadStream() function
- Added test bugs step bug27342

 - Fixed the exception
 - Added the test

SelectMgr_ViewerSelector::SetDepthTolerance() - added property defining depth tolerance type and value.
Default value remains the same (SelectMgr_TypeOfDepthTolerance_SensitivityFactor),
while new values (SelectMgr_TypeOfDepthTolerance_Uniform, SelectMgr_TypeOfDepthTolerance_UniformPixels) change behavior.

AIS_Manipulator - removed obsolete suggestion to use AIS_InteractiveContext::SetPickClosest()
for issue fixed long time ago by #0027797.

0031685: Data Exchange, STEPCAFControl_Reader - NULL dereference on translating PLACED_DATUM_TARGET_FEATURE

- Fix incorrect sharing DatumTargetType_Area
- Add check for null object

0031785: [REGRESSION] Application Framework - application crashes on reading XBF document in background thread

Class CDF_Session is removed.

Integrated previously but not described:

0029195: OCAF - ensure thread safety for different documents.

Static local variables are eliminated in PCDM package.
Global documents metadata look-up table and directory of opened documents are removed.
Look-up table is maintained now as field in instances of the CDM_Application class.
Methods providing iteration by components are removed from class CDF_Store; signature of methods returned Standard_ExtString is changed to return Handle(TCollection_HExtendedString).
Support of different "Presentations" of documents is eliminated.

Added a check to see if the ISO line intersects the bounding contour.

Catched exceptions are now passed by reference and error message is printed.
Added Standard_FALLTHROUGH to IVtkOCC_ShapePickerAlgo::SetSelectionMode().

Added custom meshing core algorithm to generate base mesh using Delabella library,
which can be enabled via IMeshTools_Parameters::MeshAlgo option or CSF_MeshAlgo environment variable.

Do not fill cirles filter upon explicit initialization.
Call base postProcessMesh functionality after initialization of circles in BRepMesh_CustomDelaunayBaseMeshAlgo.

Added Vsprintf() wrapper for vsprintf() preserving C locale.

0031323: OCAF, TObj - TObj_OcafObjectIterator does not go recursively to children if type argument is used

Added theAllSubChildren flag to the TObj_OcafObjectIterator to iterate all sub-children.
By default it still iterates only the first level of children.

The workaround for a bug occurred in MS Visual Studio 2019 / Win32 / Release configuration with disabled Whole Program Optimization is implemented.
The problem was at the line "std::stable_sort(aPairList.begin(), aPairList.end(), BRepExtrema_CheckPair_Comparator);" of BRepExtrema_DistShapeShape.cxx source file,
and linked to NCollection_Vector::Differ() method.
This workaround was suggested by MSFT team.

- Adding VS 2019 redefinition
- Update sln files for vc14,141,142