There are wheel mice that respond to Logitech probes and report
that they have only 2 buttons (such as e-Aser mouse) and this
stops the wheel from being used as a middle button. Change the
driver to always report BTN_MIDDLE capability if a wheel is
present.

Also, never reset BTN_RIGHT capability in logips2pp code - there
are no Logitech mice that have only one button and if some other
mice happen to respond to Logitech's query we could do the wrong
thing.
Signed-off-by: NVojtech Pavlik <vojtech@suse.cz>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>