fixed #3980, Tutorial about how to use box2d for collision detection
fixed #3974, side scrolling the background in box2d
fixed #3978, Tutorial about how to make a simple platformer using 3.x and box2d with collision detection
issue #3967, Tutorials about how to create a breakout game with box2d part 1
fixed #3967, Tutorials about how to create a breakout game with box2d part 2
fixed #4274.
fixed #4273, how to make a action game by cocos-html5
update catalog.
Merge branch 'master' of https://github.com/cocos2d/cocos-docs
Merge pull request #164 from u0u0/master

add toturials