[Bf-committers] Patch to add "Show/hide 3D Cursor" functionality

[Carl Olsson]

What about using the scene origin in object mode and object origin in edit
mode for any 3d-cursor-requiring operations whenever the cursor is hidden?
Half the time I do use the 3d-cursor it is first moved to the origin anyway
(eg. scaling, mirroring).
(I've never understood why there isn't an "origin" pivot mode to start
with, as that's what I want most of the time, having to move the 3d-cursor
to the origin is just extra labor.)