modifier keys not handled correctly

[joanna]

When a user presses one of the modifier keys (Ctrl, Alt, Shift) and then change focus to another appviewer window, belonging to a *different* AppVM, but still while holding the modifier key, then when returning to the original VM, it will consider the modifier key never been released and would interpret all the subsequent keystrokes as if entered together with the modifier key (that currently is not down).

Proposed solution: Check the status of all the modifier keys when an appviewer window obtains focus, and send key_down messages if necessary.

[joanna]

Fixed in gui v1.1.3:

​http://qubes-os.org/gitweb/?p=mainstream/gui.git;a=commit;h=b92d014f84fff2f5d4018b7ea8052803228e4a0b