Add feedbackd

that governs led, vibra and other user feedback based on a preselected feedback theme:

regarding the daemon i would imagine it to work like https://freedesktop.org/wiki/Specifications/sound-theme-spec/ - 
so you basically have a daemon that you tell: 'event-incoming-call', 'action-key-press', 'event-incoming-sms', '...'
 and the daemon picks the right action depending on your current profile (silent, ...)

The daemon would then do the right thing depending on the profile (and on the hardware / software parts we already 
have) - chatty, squeekboard, calls, shell then just talk to that thing via dbus asking for the right user 
notification.

see squeekboard#166 (closed)