Gremlin

- Added the 2.4.0 Tinkerpop Gremlin jars.  Not sure how you feel about this, b/c we're creeping up on being Pacer, but having the GremlinPipeline stuff in the gem is nice....
- Updated the other Tinkerpop jars that were SNAPSHOT versions to their final versions.
- Added a couple of basic specs for GremlinPipeline

Whaddya think?