This commit features fixes/improvements for problems I didn't manage to fix in time for the commit yesterday.
* Now for Meshes, the normals of the vertices in the VertexGroup are averaged and used to find the 'rotation' that needs to be applied. Unfortunately, this does not work with Lattices as they do not have normals.
* Depsgraph should now play nicely with geometry targets. Before, the constrained object's location wasn't being updated after the target's geometry was modified.