Blender Git Loki

Another refactor for 3D view's edit Transform panel. Main changes:
*Get rid of the magic numbers for median arrays, use defines instead, should make things a bit more clear and easy to edit (though there are still a bit of "array magic" on median here and there).
*Restore and extend use of RNA prop when a single (control)point of curve or lattice is selected, to allow keyframing (was added by sergey for curve radius in r41494, see [#29122], and reverted by myself in previous refactor r44599).