Implement shortcuts for

• hit ESC key to enter GlobalMode plus 1,2,3 to open a shell app
• hit ESC key to enter GlobalMode then 9,0 to navigate app stack

The exact details of this can be found here: http://wiki.magnolia-cms.com/display/UX/Initial+keyboard+support

We should make sure these shortcuts have the relevant panel scope.

CLZ NOTE:
For some keyboard commands it makes more sense to track them on the client side. For example app switching with the animation is implemented on the client side. Also if the keyboard shortcut literally just pushes the button on the screen - then you are guaranteed that the resulting action will be the same.

STILL TO DO In Future ticket:

• hit [SOMETHING] to switch between edit/preview mode
• hit "delete" key to delete an element
• hit "return" key to activate default action (typically opening an element)