Add USE_KEY_FILTER and USE_MOUSE_FILTER options

Re-applying the commit by Eric Blade <eric.blade@palm.com>
made for luna-sysmgr to here as well with modifications.

- USE_KEY_FILTER enables automatic translation of Home, End, Pause,
  Escape to equivalent CoreNavi events or Pause => Key_Power
- USE_MOUSE_FILTER enables some optional mouse input processing

Open-webOS-DCO-1.0-Signed-off-by: Jukka Honkela <jukka.honkela@palm.com>

Change-Id: I0a044cf204d2a91c5a2db2087c5e36e4480ff152