ui: convert GTK and SDL1 frontends to keycodemapdb

The x_keycode_to_pc_keycode and evdev_keycode_to_pc_keycode
tables are replaced with automatically generated tables.
In addition the X11 heuristics are improved to detect running
on XQuartz and XWin X11 servers, to activate the correct OS-X
and Win32 keycode maps.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20180117164717.15855-3-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>