Hide sidebar shortcut

This allows you to hide the sidebar with Shift+h (h for hide, as discussed with Rick).

I also did a drive-by in the shortcuts panel to expand all the shortcuts to display "Alt" instead of "A" etc.

QA:
- load the gui
- press Shift+h
- the sidebar should disappear and the environment header etc. should adjust.
- press Shift+h again and the sidebar should return
- open the machine view
- press Shift+h and the machine view should adjust.
- press Shift+h and everything should return
- press Shift+? and the listing should have "Shift+h"