Blender Git Loki

fix for 3 issues when applying a deform modifier in editmode.
- drawing face normals was broken (using wrong index).
- drawing flat faces in solid mode would display ugly tesselation normals (as if the model was made of triangles).
- drawing smooth faces in solid mode would show vertex normals based on tesselation (heavily slant in 1 direction).

now the normals are calculated and stored per polygon (will save some memory too for non tri meshes).