show and hide blocks when 2 seconds hit
Merge branch 'ludum-dare' of github.com:minggo/cocos2d-x into ludum-dare
Merge pull request #31 from natural-law/ludum-dare

Check the position index when getting the block.
Add logic to show a block forever.
Merge branch 'ludum-dare' of github.com:minggo/cocos2d-x into ludum-dare
Add fade out effect.