Normalize class names for fix conflict issues with old project.
Change some descriptions tool tips text
Revert presets base code. Now, use Blender code again.
Change some class names for fix conflict with old project
Link 'premult' to transparent background value
Fix mismatch 'phase function' exporter parameter( report by wizofboz )
Small typo changes
Merge branch 'rc2' of https://github.com/TheBounty/Blender-Exporter into 0.1.6_rc1

Conflicts:
	prop/yaf_light.py
	ui/properties_yaf_light.py