Remove the duplicate-property check from the normal execution path.
Removed some more unused code.
Merge remote-tracking branch 'upstream/master' into 2.2-remove-duplicate-property-check

Conflicts:
	community/kernel/src/main/java/org/neo4j/kernel/impl/core/NodeManager.java
Merge pull request #3330 from chrisvest/2.2-remove-duplicate-property-check

Remove the duplicate-property check from the normal execution path.