Blender Git Loki

Hacky fix for Mode Switch Pie Menu overflowing to a submenu on GP Objects

With the introduction of the GP editing modes to the object/workspace
modes enum, this introduced a number of issues for the Ctrl-Tab mode
switching pie menu, e.g.
* To access any of the GP Editing modes, you had to first navigate to
the "More" sub-pie, before being able to see these values. In practice,
this was tricky to use, and not ideal.
* Particle Editing mode was also moved into a sub-pie by itself

This was due to the following reasons:
1) Pie Menus for Enums use the "static" enum define to determine
where items should go. This was done to ensure spatial consistency
of items (e.g. Edit is always in the "east" position).
2) Each pie menu layout is only allowed to contain 8 items.
(i.e. so that movements can be less precise, corresponding to the
main compass directions only)
3) The nature of the modes menu means that there is never any situation
where all menu items need to be visible at the same time. Usually,
there are only between 2-5 items in that menu at a time, and at least
6 of the items are only valid for a single object type each.

Several other solutions were tried, but this hack is the simplest fix.