Blender Git Loki

Actions can now be made single-user from the Outliner

* Use the same method as from unlinking actions to do this.
* Split off the make single-user code used for the ID-browser into a
function in blenkernel which can be used elsewhere. Getting materials
to also work using this method proved to be a bit too tricky (due to
the whole messy ob vs obdata situation), so I haven't done that.