Introduce ternary logic in Cypher

o Make Predicate return Option[Boolean] instead of Boolean
o Introduce isTrue that returns false for all cases except when the
   predicate returns Some(true)
o Add logic for IN, ANY, ALL, SINGLE and NONE to handle nulls
o Add a new section on working with nulls to the manual
Remove MSI installer

This never shipped a single MSI and is not plumbed into the reactor.
Merge branch '1.9-maint' into merge

Conflicts:
	community/cypher/src/test/scala/org/neo4j/cypher/internal/executionplan/builders/IndexQueryBuilderTest.scala
	community/kernel/CHANGES.txt
	community/kernel/src/main/java/org/neo4j/graphdb/GraphDatabaseService.java
	community/kernel/src/main/java/org/neo4j/helpers/collection/Iterables.java
	community/kernel/src/main/java/org/neo4j/kernel/InternalAbstractGraphDatabase.java
	community/kernel/src/main/java/org/neo4j/tooling/Clock.java
	community/kernel/src/main/java/org/neo4j/unsafe/batchinsert/BatchGraphDatabaseImpl.java
	community/kernel/src/test/java/org/neo4j/test/EmbeddedDatabaseRule.java
	community/server/CHANGES.txt
	community/server/src/main/java/org/neo4j/server/AbstractNeoServer.java
	community/server/src/test/java/org/neo4j/server/helpers/ServerBuilder.java
	community/shell/src/main/java/org/neo4j/shell/kernel/ReadOnlyGraphDatabaseProxy.java
	enterprise/backup/src/main/java/org/neo4j/backup/BackupImpl.java
	enterprise/backup/src/main/java/org/neo4j/backup/BackupServer.java
	enterprise/backup/src/main/java/org/neo4j/backup/OnlineBackupKernelExtension.java
	enterprise/cluster/src/main/java/org/neo4j/cluster/protocol/cluster/ClusterConfiguration.java
	enterprise/cluster/src/main/java/org/neo4j/cluster/protocol/heartbeat/HeartbeatState.java
	enterprise/com/src/main/java/org/neo4j/com/Client.java
	enterprise/com/src/main/java/org/neo4j/com/ResourcePool.java
	enterprise/com/src/main/java/org/neo4j/com/ServerUtil.java
	enterprise/com/src/test/java/org/neo4j/com/MadeUpServer.java
	enterprise/ha/CHANGES.txt
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/HighAvailabilityConsoleLogger.java
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/HighlyAvailableGraphDatabase.java
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/cluster/HighAvailabilityModeSwitcher.java
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/com/master/MasterImpl.java
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/com/master/MasterServer.java
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/com/slave/SlaveServer.java
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/lock/LockManagerModeSwitcher.java
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/lock/SlaveLockManager.java
	enterprise/ha/src/test/java/org/neo4j/kernel/ha/TestBasicHaOperations.java
	enterprise/ha/src/test/java/org/neo4j/test/ha/ClusterTest.java
	enterprise/server-enterprise/src/test/java/org/neo4j/server/enterprise/helpers/EnterpriseServerBuilder.java
	packaging/standalone/src/main/distribution/shell-scripts/bin/neo4j
	packaging/standalone/standalone-advanced/src/main/distribution/text/advanced/CHANGES.txt
	packaging/standalone/standalone-community/src/main/distribution/text/community/CHANGES.txt
	packaging/standalone/standalone-enterprise/src/main/distribution/text/enterprise/CHANGES.txt
Fixed issue with unique relationship creation response codes in REST.
Removed the ability to lock relationships via NodeManager, part of the work to ensure that we never acquire locks before we've enlisted data sources.
Added additional HA logging.
ImpermanentGraphDatabase.cleanup should delete all nodes

This fixes a bug where certain graphs could confuse the cleanup method
into leaving some nodes behind.
Makes cypherdoc commit each query separately so constraints and indexes can be handled.
Brings in resizing of the live console.
Adds an introduction page on labels, indexes and constraints.
Merge pull request #1459 from jakewins/merge

Merge 1.9
Revert "Added additional HA logging."

This reverts commit 9da8386a42b0d8554346d744df1052ac75703f07.
Merge pull request #1473 from jakewins/master

Revert "Added additional HA logging."
Add missing test strings to label tutorial.
Make OtherThreadExecutor implement Closeable to make orderly thread
shutdown easier.

o Callers can now use try-with-resources.
Make NestedTransactionLocksIT more readable.
Ensure that all tests close transactions reliably.

o Recent changes to database shutdown mean that we now wait for transactions
   to finish when shutting down. This mean that each of the many tests which did
   not close their transactions was hanging for 20 seconds before failing.
Merge pull request #1463 from chrisvest/fix-impermanent-graph-db-cleanup

ImpermanentGraphDatabase.cleanup should delete all nodes
Merge pull request #1462 from simpsonjulian/goodbye-msi

Remove MSI installer
Rename the GCR Cache to High-Performance Cache
More robust shutdown of sub processes.

o Make PipeTask correctly handle end of input streams.
o Un-export RMI callback so that RMI Reaper thread can exit on owning process.
Merge pull request #1472 from digitalstain/election-logging

Revisits logging in ElectionState and ClusterConfiguration