unique button callbacks
Merge branch 'dev' of https://github.com/sunriseJS/sunriseJS into dev

# By JGerdes
# Via JGerdes
* 'dev' of https://github.com/sunriseJS/sunriseJS:
  added a sounds, game uses it
  created audio player
  loading sounds before starting the game
  ressource loaded is able to load sounds
refactor collision solver to use collidingGroups instead of collidingObjects
removed collidingObjects from groups