Added Projectile class

- also implemented lifetime, which removes the projectile after that time
- added GameObject.collideRect which will determine whether or not the objects collide by rects (need to worry about rotation here?)
After much trying, I think the rectangle collision is working well, pixel perfect isnt actually checking alpha yet though :(
Fixed a silly typo in GameObject.collideRect, fixed that method
I think GameObject.pixelCollide is working well now

- also optimized to only check a subrectangle of pixels instead of all of obj2 against obj1
Added a container that allows everything to follow the player

- also tweaked pixel collisions more
Added ndgmr collision detection library for createjs

Works better than my solution...keeping it!
Added other layers all contained in level, which is then moved based on the player's POV
Added idea project; changed GameObject to Container that has an image; added a HUD class
Added scrolling background, auto-resize
Load shiplist from assets/ships.json
Particle system

basic particle system in place that makes use of spritesheet anims
Added basic engine glow capability
Changed preloader to auto-load all images. For now only json files need to be statically specified in the manifest
Working on abstracting Screen away from SpaceDominationGame
Merge branch 'master' into gh-pages
Added output files