Specify generic.
MetaProperty.label() == MetaProperty.key(). Added testing around Neo4jMetaProperty indexing.
Merge remote-tracking branch 'origin/master' into io-pain

Conflicts:
	gremlin-test/src/main/resources/com/tinkerpop/gremlin/structure/util/io/graphson/grateful-dead.json
	gremlin-test/src/main/resources/com/tinkerpop/gremlin/structure/util/io/graphson/tinkerpop-classic-typed.json
	gremlin-test/src/main/resources/com/tinkerpop/gremlin/structure/util/io/graphson/tinkerpop-modern-typed.json