Blender Git Loki

Pies: Support object mode pie with more than 8 items

Fixes changing position of items introduced in rB669fdca6818b.
Since release is comming closer, I decided to try implementing support for more than 8 items per pie. This would require bigger changes which might not be safe to apply before relase though. For now, this should be good enough.

There are a few ugly things in the patch, but improving would not be trivial and require bigger changes. Was already tricky enough to get this working ;)

Reviewers: campbellbarton

Projects: #user_interface

Differential Revision: https://developer.blender.org/D1800