+ remove warnings regarding #pragma(push)

It appears that
1. travis sometimes uses other than the default linux distribution (trusty, 14.04) specified here:
    https://docs.travis-ci.com/user/reference/overview/#linux
2. the default setup of mingw on xenial (16.04) has trouble with std::mutex, which is why lib3mf builds fail on this machine.

Thus, this commit enforces trusty as distribution for the mandatory mingw-builds.

Reading
- relative progress is now based on amount of data read
- progress identifier is still defined via which element is currently being read

Writing
- relative progress is now based on number of resources and attachments
- progress identifier is still defined via which element is currently being written

Performance:
- replaced inefficient data structures (list or vector + linear search for elements)
  by more apt datastructures (map (unordered_map, multimap) + lookup) in
  a couple of occurences

This major commit prepares v2 of lib3mf
- adds the Automatic Component toolkit
  - this removes the COM interface
  - autogenerates language bindings for multiple languages
- reworks the way in which properties are handled
- implementes multiproperties and compositematerials
- adds basic (and automatic) documentation using sphinx / https://readthedocs.org/
- improves/changes lib3mf in multiple other minor ways
- ... but has several open issues left

* add CImportStream_Shared_Memory and CImportStream_Unique_Memory

* Fix bad_alloc -Wcatch-value from GCC 8

* use tab instead of 4 spaces

* increase patch version to 1.8.2

Specify next release to be v1.8.1

* Fix handling of installation dirs using official setup.

* Use project version setting (requires cmake 3.0.2).

* Add options to disable included zlib and libzip.

* Add pkg-config definition.

* Move NMR_COMVersion.h to global .gitignore file to clean up installation.

* Fix version information in the Windows DLL.

* use ole32 when compiling with MINGW in Windows for UUIDs

* use winresrc.h instead of winres.h

* remove ole32 link dependency

* add mingw shell script

* add mingw support to travis-cli

* fix travis before_script

* add cmake cross compile support to cmake

* remove tobydox dependency

* use mingw from /usr instead of  /opt

* remove test from travis mingw build

* remove tets generation for linux mingw

* fix mingw cmake script

* add LIB3MF_TESTS at cmake toolchain

* reenable tests in mingw cmake