Blender Git Loki

Interface drawing tweaks:

* Made the shaded ends of popup menus the right shape,
when the button is aligned, connected to another button.
Found by desoto, fix by desoto

* Made the icons inside icon buttons scale up with zoom,
rather than just sit down in the bottom-left corner. The
scaling up is rather ugly - consider this a temporary
measure until we can find a nicer solution, on the
backburner for 2.35. Found once again by Bugmaster
Desoto, fix by ton.