Allow to hide the main menu.
Allow to hide the main menu.

The main menu is fairly small (still?). So allow power user to reclaim
screen estate by adding the "show/hide menu" action.

sandsmark/zanshin,sandsmark/zanshin,kolab-groupware/zanshin,kolab-groupware/zanshin,sandsmark/zanshin,kolab-groupware/zanshin