add preSet
issue #2351 compress  resource "video\png"
issue #2351 add file "Background.js"
issue #2351 compress  javascript  file
issue #2351 use sprite  replace tileMap
fixed #2351 limit enemyMax
fixed #2351 delete setColor
fixed #2351 change number of preSet
Merge pull request #181 from xingsenma/MoonWarriors2

fixed #2351: Improve MoonWarriors performance for mobile browsers