fix fireball-x/dev#360: support reload current scene
fix fireball-x/dev#360: support reload current scene

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