Blender Git Commit Log

Fix T39020: Undo/Redo/History buttons missing in "Edit mode"

Remotely based on patch by kevindietrich (Kévin Dietrich), but using
a single generic panel here, as suggested by UI team.

Note we add this panel in all modes (only one tweak in scuplt mode,
where there is no history menu generated it seems, unlike other
'paint-like' modes), we can decide to move it into its own tab later.

Differential Revision: https://developer.blender.org/D733