Fixed issue with `CREATE UNIQUE` when using array parameters.

Arrays were compared by reference instead of equality which lead
to the unique constraint to fail.
Merge pull request #3488 from pontusmelke/issue2038

Fixed issue with `CREATE UNIQUE` when using array parameters.
Merge remote-tracking branch 'upstream/2.0-maint' into 2.1-maint

Conflicts:
	community/cypher/cypher/src/test/scala/org/neo4j/cypher/CreateUniqueAcceptanceTest.scala