* [clang-tidy] Do not use else after return

Found with readability-else-after-return
Signed-off-by: Rosen Penev <rosenp@gmail.com>

* [clang-tidy] Convert several loops to be range based

Found with modernize-loop-convert
Signed-off-by: Rosen Penev <rosenp@gmail.com>

* [clang-tidy] Replace deprecated C headers

Found with modernize-deprecated-headers
Signed-off-by: Rosen Penev <rosenp@gmail.com>

* [clang-tidy] Use auto where applicable

Found with modernize-use-auto
Signed-off-by: Rosen Penev <rosenp@gmail.com>

* .clang-tidy: Add these checks

* Run clang-tidy modify with modernize-use-auto
* Use using instead of typedef

* [clang-tidy] Replace C typedef with C++ using

Found with modernize-use-using

Added to .clang-tidy file.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

* [clang-tidy] Remove redundant member init

Found with readability-redundant-member-init

Added to .clang-tidy

* [clang-tidy] Replace C casts with C++ ones

Found with google-readability-casting
Signed-off-by: Rosen Penev <rosenp@gmail.com>

* [clang-tidy] Use default member init

Found with modernize-use-default-member-init
Signed-off-by: Rosen Penev <rosenp@gmail.com>