Changed the way key triggers and messages are named.

Key triggers:
  'key-pressed:*'   --> press key event
  'key-released:*'  --> release key event
  'key-event:*'     --> any key event for the key

Key messages:
  '*_key' --> state of the * key
              (for instante: 'a_key', 'left_key', 'space_key')
Merge branch 'keyboard-newnames' into dev