Add sanity checks and poll function in variant/author deletion operators
Prevent Add/Remove Variant/Author from showing up in search results
Adjust to new template_list syntax in Blender 2.6X (where X = TODO)
First implementation of custom texture preset editing
Set "toggle variant visibility" operator to INTERNAL

This makes it not show up in the menu.
Edit Zusi specific settings of active material slot, not the first one
Fix name of D3DTSS_COLOROP property
Write ALPHAREF value as string, not int
Make the add-on work with Blender 2.63a and above
Add information on minimum required Blender version