Refactored some BoundRelationship logic out of...

Relationship.
Refactored methods in MultipleNodes and...

RelationshipQueryset for easier extensibility.
Added Relationship._reverse_relationship_type...

for asymmetric relationships on models.
Removed the RelationshipBase metaclass- it ...

represents an older effort at relationship models (#1).
Removed query type restriction to allow querying..

related abstract models.
Massaged the Groovy script binding to make...

accessing the neo4django utilities easier from other scripts.
Merge branch 'relationship-cleanup' of github.com:mhluongo/neo4django