fb: give the system proper values back if it is a hw key or navbar device

as well allow this behaviour to be overwritten by system.prop like
it is suggested by google.

Needed to show eg the menu button in apps correct on the different
device types

Change-Id: Ic6145fb70ec9b67802d6d7a5ce70c21f3452cdcd
fb: add big menu support back

some in our team as well user want it urgently so we do it for
now till new Slim recents is back then we handle it so or so in
another way and do not need the recents button anymore and can
use the big menu button as permanent and get rid off the smal
3dot completly,

Change-Id: I785b83140725f3f3e8b274081d764a0e35b8946c
Merge remote-tracking branch 'github/kk4.4' into slimkk