+++++
**Features**
- Add support for object deletion in PyEcore. The delete feature allows the user
to remove parts of the model. Those parts can be a simple element or a sub-graph
if a container object is deleted. The delete tries to keep up to date a special
list that gathers the non-inverse navigable relation. When called, the method
gathers all the EReferences of the object to delete and these special relations.
It then update the pointed references. There is a special behavior if the object
to delete is a proxy. If unresolved, the proxy can only be removed from the
main location, but not from the remote one. If resolved, the proxy keep the
classical behavior. This behavior tries to match the EMF-Java one: https://www.eclipse.org/forums/index.php/t/127567/
**Bugfixes**
- Fix double resources loading in same ``ResourceSet``. When two ``get_resource(...)``
call with the same URI as parameter were done in the same ``ResourceSet``,
two different resources were returned. The new behavior ensure that once the
resource had been loaded, a second call to ``get_resource(...)`` with the
same URI will return the resource created in the first place.
**Miscellaneous**
- Make use of ``ChainMap`` for ``global_registry`` management (simplify code).
- Raise a better exception when a 'broken' proxy is resolved.
- Add small performances improvement.