Merge pull request #1358 from cleishm/cypher_clause_warnings

Require a WITH when going from OPTIONAL MATCH back to MATCH
Fix warning in CypherException
Remove extraneous println's
Fix type check for length("string") in cypher
Add size(['a', 'collection']) funtion to Cypher
Use correct type for possibleStartPoints in VarLengthRels
Make PathType a fully-fledged type
Disallow the use of a Path as a Collection