fixes#194 Starting multiple screen sessions (lost key event)
You can test this by using the mouse demo, which now supports pressing
CTRL-Z. This does not actually suspend the demo, but starts a subshell
which takes over. After the subshell is exited, the demo takes control
of the screen back. This can be done multiple times, and it is possible
to start multiple "nested" iterations of the demo this way.
Garrett D'Amore