function Prefab( o, filename )
{
	this.filename = filename || null; //base file
	this.fullpath = filename || null; //full path 
	this.resource_names = []; 
	this.prefab_json = null;
	this.prefab_data = null; //json object
	this._resources_data = {}; //data as it was loaded from the WBin

	if(o)
		this.configure(o);
}
Prefab work in two ways: 
- It can contain a node structure and all the associated resources (textures, meshes, animations, etc)
- When a node in the scene was created from a Prefab, the prefab is loaded so the associated resources are recovered, but the node structure is not modified.

@class Prefab
@constructor