Add FieldOfView token type (fixes #245)

"FieldOfView" has its own token type (basically just one float), if it's missing the camera will keep reverting to default FOV in ASSIMP.
Handle both types of element names

MAX seems to add an "s" to "Binormal" and "Tangent" when exporting
Merge pull request #322 from Gargaj/patch-2

Handle both types of element names
Merge pull request #321 from Gargaj/patch-1

Add FieldOfView token type (fixes #245)
Obj: make mtl importer accept kd, ks etc. as well (Kd, Ks being the correct form). This is for keeping up compatibility with assimp's own Obj exporter, which has been inaccurate about this since inception.
Split off postprocessing progress
Granulate file loading too
this isn't needed anymore
avoid division by zero
add basic framework (files, etc)
convert exporter from tools/assimp_cmd
follow assimp code style (tabs)
- add compression support
- remove unneeded code
- change log warning to exception
- document
add basic framework for importer
Fix wrong nesting

Otherwise doesn't compile if ASSIMP_BUILD_NO_3DS_IMPORTER is defined because the #endif is inside the namespace block
add info + header check
Merge pull request #324 from Gargaj/patch-1

Fix wrong nesting
start importer, load nodes
add to cmake
fix code style