allow store to receive a collection as python list instead of rdf:first/rest triples

[wrobell]

At the moment rdflib provides a RDF collection as rdf:first/rest triples. A store, which really requires a collection (i.e. list), has to parse such triples again. This is inconvenient and slow.

Would it be possible to add a configuration option to the store interface, which would say that a store accepts collections as lists and then a parser would provide any RDF collection as a Python list?