Blender Git Loki

Outliner: Remove need to hold shift when parenting

https://developer.blender.org/D3812 discussed reasons why holding shift
to parent was needed. Now in the outliner we show child-parent
relationships clearly in View Layer mode so this extra modifer key is
not needed.

When dropping over an object name the parent operator is used, and when
dropping anywhere outside the object name will move to collection.