Some saitek mice implement a tristate button (for switching button mappings in
the original driver) by keeping one of three (non-physical)
buttons constantly pressed.

This breaks X and probably other userspace software.

This patch implements a quirk for the R.A.T.7 and M.M.O.7, tracking the mode
and generating presses of a single button if it changes.  Also the missing
release event is generated instantly.
Signed-off-by: Harald Brinkmann <hbrinkmann@braincalibration.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>