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' of git://github.com/splondike/Android-Terminal-Emulator into splondike-hardware-ctrl-sticky
Refactor this change to use the standard onPause/onResume protocol.

An alternate idea would be to share the same KeyListener across all
open terminal windows. That might be better.