Fix problem about not using indexes when multiple labels are present on a node

o fix conflicts between Ronja rewriters and legacy planner
o added more index acceptance tests
o fix the legacy planner builder to make sure indexes can use values generated by unwind
Merge branch '2.1-maint'

Conflicts:
	community/cypher/cypher-compiler-2.1/src/test/scala/org/neo4j/cypher/internal/compiler/v2_1/planner/SimplePlannerQueryBuilderTest.scala
Merge pull request #2546 from davidegrohmann/2.1-merge-master

Merge 2.1-maint into master