Cleaned nodes on dispose and set _isLoaded to false so that the whole state would be reset
Cleaned nodes on dispose and set _isLoaded to false so that the whole state would be reset

RaananW/Babylon.js,BabylonJS/Babylon.js,sebavan/Babylon.js,RaananW/Babylon.js,BabylonJS/Babylon.js,sebavan/Babylon.js,RaananW/Babylon.js,sebavan/Babylon.js,BabylonJS/Babylon.js