Add Proxy resolution support

Proxy resolution should happen directly in the EObjectBuilderImpl on load. It must be activated by a load option.

There must the following modes:

None (Default) - No Proxies will be resolved if present - getEObject(, false) will be called and if a object is already in ResourceSet, this will be set instead of a proxy force load - getEObject(, true) will trigger the resource set to load the EObject from cache - a list of resources (or a map) must be supplied that represent the pool of Objects to use instead of proxies