Add Zend\Db\TableGateway support

This PR adds preliminary Zend\Db\TableGateway support. The unit tests still need a bit more work but are well on their way.  Will do some more testing on this once it is merged because it is a royal PITA to attempt to live test it otherwise.

Also fixed MongoDb Connection test as the class name was wrong (still would have worked anyway).  Also added some files to the gitignore.