Add FileInputStream helper functions to GraphMLReader
Add FileOutputStream helper functions to GraphMLWriter
Add FileInputStream helper functions to GMLReader
Add FileOutputStream helper functions to GMLWriter
Add FileInputStream helper functions to GraphSONReader
Add FileOutputStream helper functions to GraphSONWriter
Remove the final keyword from GraphSONUtility.

When parsing GraphSON stream, it may be required to extends
the functionality of the GraphSONUtility class and provide more specific implementation
for special cases.
Compatibility with Java 5
This is required in order to make it easier to extend some blueprints interfaces. Notably com.tinkerpop.blueprints.Index. The parameterized type <T extends Element> necessitates that OrientElement be public.
make rollback check the status of the transaction before rolling back
Bumping java back to 1.6.

We went to 1.5 recently because we assymed that we weren't using 1.6 features anywhere, but that wasn't really true as the @Override annotation was being used in a 1.6 way.
small tweak to test case to ensure proper deleting of tempory directory.
Fix bug in OrientGraph.getVertices #348
Travis was timing out on dependencies
added Element.remove() and Vertex.addEdge(Vertex,String). Easy for all implementations. Hard for wrappers. Lots of Wrapper code changed.
Fixed a ConcurrentModificationException bug in TinkerGraph. JavaDoc.
updated LICENSE year.
fixed #354. transaction closed after indices loaded.
Added tests to cover transaction consistency across threads.
Organize neo4j dependencies in parent POM.

Avoid repeating versions in child poms dependencies by inheriting dependencies
from parent POM dependencies management.