Blender Git Loki

Patch [#25409] Changes to panels header "open/close" and "drag" zones
Submitted by: Peter Tarasenko (pit)

This patch switches the screen real-estate given to the "open/close"
and "drag" zones for panels.
- Now, the entire header is used for resizing (open/close) panels
instead of just the triangle widget being used for this. This makes it
a larger target for clicking on, making it easier to do so (Fitt's Law
in action!)
- Dragging panels now is relegated to the "grabber" zone on the top-
right corner only now. This reflects the lesser importance of panel
reordering in the panel designs now over being able to open/close
them.