Blender Git Loki

* disabling symmetry feathering and clipping. more research is needed before I can make it work right, dropping it until later
* "Lock Brush Size" takes the current brush size, and keeps it the same size no matter how the object is viewed.
* Zooming in and out dynamically resizes the brush retical. This also lays the foundation for a fancy brush retical ala Sculptris
* commented out a couple of unused fields from struct Sculpt. This struct adds so little, should be unified with Paint later
* made the hard limit for brush size 1-2000, to allow it to grow to larger than the screen when using lock size. UI soft limit is still 1-200