remove obsolete qudevhelper and adopt mouse and touch plugins

remove obsolete qudevhelper and adopt mouse and touch plugins

The QUDevHelper class is now replaced by QUDeviceHelper class.
All evdev input plugins are using the new udev helper now to enable
hotplugin for keyboard and mouse input.

EvdevTouch plugin still only uses the first detected device by udev,
this cannot be tested on my side, due to the lack of multiple touch input devices.

Change-Id: I01a4cfe1a80000bfb27c67a2f53faf560906b73c
Reviewed-by: Laszlo Agocs <laszlo.p.agocs@nokia.com>