Blender Git Loki

- fixed slow file reading of vertex deform groups.

found out that per vertex, per deform group, a heavy function was called
to get an address from a huge array. that address even didnt exist, was
not written in the file... just removing the code makes .blend file
reading happy again.

check it by parenting a 40k vertex mesh, to an armature with "use
armature" and "create vertex groups". save and load file.