Merge branch '2.1-maint' into 2.1-merge

Conflicts:
	community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelTransactionImplementation.java
	community/kernel/src/main/java/org/neo4j/kernel/impl/api/state/TxStateImpl.java
	community/kernel/src/main/java/org/neo4j/kernel/impl/nioneo/xa/NeoStoreTransaction.java
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/ParallelBatchImporter.java
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/store/BatchingNeoStore.java
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/store/BatchingWindowPoolFactory.java
	community/kernel/src/test/java/org/neo4j/unsafe/impl/batchimport/ParallelBatchImporterTest.java
	community/kernel/src/test/java/org/neo4j/unsafe/impl/batchimport/store/BatchFriendlyWindowPoolFactoryTest.java