Blender Git Loki

NLA SoC: Fixes for bugs in transform code from previous commit

* The code to move strips between tracks now works (though it can still be a bit too eager to change tracks half-way through some transforms).
Strips are moved up/down one strip at a time, depending on whether there is any space in the next-track in the direction you direct it to move in.

* Auto-snapping works again. Also enabled snap-to-marker option for Graph Editor here.