Hide Top Bar

[alex]

Add an option to hide the top bar, to free up useful space for widgets.

When the top bar is hidden, all of its controls should be accessible in a different way:

• project switcher - via the main menu, and the tray menu (already done)
• manage projects - via the main menu (already done)
• shelf items - via a small area at the right side of the workflow tabs area
• edit mode toggle - via the main menu (already done)

[rugby]

I'd like to propose a simple compact mode to save screen estate like this:

[sue]

I like this suggestion.

[niutech]

I've made a compact toolbar in my Freeter fork.