Re-applied commits of last 2 days.
Make JDK6 compatible.
Null check of context for transactions.
Fixed problem on REXSTER test cases when commit/rollback/stopTransaction was called on invalid graph instance
Merged changes
Add back JDK6 support.
Tests around vertex properties and transactions.

One is an untest that fails for neo4j.  the other passes for all graphs.
Merge remote-tracking branch 'origin/23'
Removed isRDF check from test from the 23 branch.
Move all untests to bottom of suite.
Fixed case when dirty documents are attached
Committed transaction prior to running GraphTestSuite testStringRepresentationOfVertexId if a transactional graph. #398
Merge remote-tracking branch 'origin/23'
Fixed bug on indexes where the key is not a string
Merge branch 'master' of git://github.com/tinkerpop/blueprints
OrientDB: fixed issue against index using different types than String
bumped to support Neo4j 1.9
merged master and static String Lucas latest SKIP LIMIT work.