Support sending full Gremlin queries directly to Rexster

- add GraphClient and RexsterClient classes
- Connection.open() no longer requires settings parameter
- add dependency to Mikeal's request
Attempt to ready Schema associated .groovy file if existant
Allow definition of Gremlin queries bound to Schema statics in seperate .groovy file

- add GroovyParser for parsing .groovy files
- update doc
Merge branch 'gremlin'
Bump to v0.1.0
Fix doc
Merge branch 'master' into develop
Elements (vertices and edges) fetched from DB can now be retrieved as model if available

- add ElementInitializer class
- add Gremlin class