Blender 2.64

- This release was targeted at improving Blender for the Mango open movie project, along with integrating branches and patches from the past years.
- The focus was on creating a full VFX pipeline, with improved motion tracking using a planar tracker, easier green screen keying, and a new mask editor.
- A new tile based compositing system was added, along with more advanced color management.
- Cycles rendering got dozens of smaller features and improvements resulting from its use in production.
- Sculpting now supports masks, and a skin modifier was added to quickly create a model from skeletons.
- The game engine got improved shadows and physics options, and Collada export now has more options to tune for exporting to other game engines.