update query12 api/steps & cypher impls for updated spec
update query12 test and test data for updated spec
clean LdbcTraversers by removing unused traversal descriptions and adding comments to all remaining traversal descriptions
update query14 tests to check for 2 more cases (1) start person=end person (2) no paths exist between start person and end person
update neo4j JDBC driver from 2.0.4 to 2.1.4 (error with shortest path query is still present)
remove unused traversal descriptions from LdbcTraversers
update query8 cypher & api/steps impls to be consistent with latest spec (remove recursive conversation component, only 1-hop replies considered now)
update tests accordingly
update all tests to also check for correct LIMIT implementation