Merge pull request #22 from BrynCooke/master

Add param support to @GremlinGroovy --- Merged. Thanks. Can you please provide some documentation around this in the http://frames.tinkerpop.com Wiki.
removed sideeffect in Gremlin annotation demos as now you can access the pipeline with AsMap.
updated CHANGELOG. @BrynCooke.
Fixed #23 .. Also, removed caching layer in GremlinGRoovy annotation as GremlinGroovyScriptEngine maintains caching.
another test case for arbitary return object from GremlinGroovy annotation.