Merge pull request assimp#1631 from assimp/kimkulling-410_prep

Update to 4.1.0

CHANGES: add documentation of featureset for 4.0.1

Update CHANGES

Merge pull request assimp#1347 from rickomax/master

Fixed many FBX bugs

Merge pull request assimp#941 from assimp/feature/issue_940

Feature/issue 940

Version: prepare 3.3 version.

CMake: set version number to 3.2

Update doxygen documentation. Drop custom stylesheet.

Merge branch 'master' of https://github.com/assimp/assimp

Release candidate 2 : 3.1

Signed-off-by: Kim Kulling <kim.kulling@googlemail.com>