Exporter:
Removed THREE prefix from custom attributes
Added custom attributes for
- blending type (material)
- magFilter (texture)
- minFilter (texture)
- mapping (texture)
- export (object)

Added more function to api.texture to support new attributes
Added anisotropy to texture attributes output
api.object.nodes now checks threeio_export boolean
Log path prints at end of succesful export

Loader:
Support for more texture attributes added