Extracted keycode constants from TermKeyListener
Added create and switch window/tab keyboard shortcuts

Switch forward with Ctrl+Tab, back with Ctrl+Shift+Tab
Create new with Ctrl+Shift+N
Added paste from clipboard shortcut (Ctrl+Shift+V)
Fixed hardware control 'stickyness' when switching views

To reproduce bug:
1. Hold down ctrl on a physical keyboard.
2. Create a new window using the (+) icon.
3. Type exit to close the new window.
4. Attempt to type into the original, control key
   is still flagged as being pressed.
Merge branch 'hardware-ctrl-sticky'