Merge branch 'digitalstain-1.9-fix-versioned-election' into 2.1-maint

Conflicts:
	enterprise/cluster/src/main/java/org/neo4j/cluster/protocol/atomicbroadcast/multipaxos/context/ClusterContextImpl.java
Updates changeslogs for 2.1.5
Removes unecessary LogEntryShuffler ported over from a merge
Fixes compilation error in ElectionContextTest. Static import Mockito.mock()
Fixes a page write race in the batch importer

regarding creating the neostore and moving on to starting the actual
import. This would have been a problem when the IoQueue was used as the
writer.

This commit adds a flush+wait after creating the neostore to remedy this
problem.
Merge branch '2.1-maint'

Conflicts:
	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/server/CHANGES.txt
	enterprise/cluster/src/main/java/org/neo4j/cluster/protocol/atomicbroadcast/multipaxos/context/ClusterContextImpl.java
	enterprise/cluster/src/test/java/org/neo4j/cluster/protocol/election/ElectionContextTest.java