Blender Git Loki

2.5 / Area management
* implementation of a proposal from during Wintercamp:
- with SHIFT-LMB drag of area corner the area gets
duplicated into a new window.
This is the old "Rip Area" operator with a new,
better name. The old menu and hotkey are now gone.
This means we have currently split, join and now
duplicate/copy area into new window in the area
actionzones.