update polymer to v0.5.1.
update polymer to v0.5.1.

fireball-x/deprecated_engine,knoxHuang/engine,fireball-x/deprecated_engine,cocos-creator/deprecated_engine,knoxHuang/engine,cocos-creator/deprecated_engine,fireball-x/deprecated_engine,cocos-creator/deprecated_engine,knoxHuang/engine