created SoundLibrary
clean and remove bubbles from Game
added some tatooine backgrounds
clean the Bubble class
changed background, now InvisibleWalls is restricted to the background's ground
This background looks better
wip
refactor: encapsulated touch events handling.
fixed direction the jedi faces when parring lasers
fixed: sprites floating hight should be managed with getSpriteOffsetY()
fixed bug that made the Jedi to look always to the left when stopped.
add second bubble
Add lower resolution Luke
improved animation/cooldown sincronization
fixed animations
Added DarthVader character
* updated Jedi sprite-sheeet
* updated StormTrooper sprite-sheet

big cleanup