Merge remote-tracking branch 'upstream/2.1-maint'

Conflicts:
	community/cypher/cypher-compiler-2.1/src/main/scala/org/neo4j/cypher/internal/compiler/v2_1/mutation/DeleteEntityAction.scala
	community/kernel/src/main/java/org/neo4j/kernel/impl/nioneo/xa/NeoStoreTransaction.java
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/ParallellBatchImporter.java
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/store/BatchFriendlyNeoStore.java
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/store/BatchFriendlyWindowPoolFactory.java
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/store/io/IoQueue.java
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/store/io/WriteJob.java
	community/kernel/src/test/java/org/neo4j/unsafe/impl/batchimport/store/BatchFriendlyWindowPoolFactoryTest.java
	community/kernel/src/test/java/org/neo4j/unsafe/impl/batchimport/store/io/IoQueueTest.java