Blender Git Loki

Fix: ANIM_animdata_update() was not handling post-edit updates on GP channels

This may have resulted in situations where the order of GP keyframes was
incorrect (leading to some frames not being able to be found), or in some
redraw problems when trying to delete GP keyframes (that I was getting earlier,
but can't seem to reproduce now)

TODO: We now need to hook up a proper api to do the GP key sorting