Logging performance optimizations:
* Added custom Jetty logger that caches isDebugEnabled
* Changed LogbackService to cache isDebugEnabled
* Added isDebugEnabled check before toString() in HighPerformanceCache
Only add security filter if there are security rules
License header fix
Debug cache is now no longer static.
Added comment that the request log needs to decorate all other handlers.
Added +UNWIND+ to Cypher

UNWIND can be used to transform a collection into individual rows.
Minor changes to UNWIND

o Added more a few more tests for edge cases
o UNWIND now does not remove anything from scope,
  only adds a new identifier for the elements
o Tweaked the documentation
Add UNWIND to shell
Fix GC overhead of XidImpl

- Only allow equality of XidImpl instances, not the Xid interface,
  reasoning being that hashCode cannot be equal to other xid impls since
  there is no standard, and getting a xid that isn't a xidimpl is an error,
  since the xids come from our tx manager, we do not manage other xids.

- Don't copy the branchID and globalId arrays on every equaylity check
Changes ClusterSettings.server_id to be an InstanceId instead of an integer
Fixed a memory leak in DiskLayer on HA restart.

- DiskLayer no longer uses an anonymous inner class for the lazy property
  loading, as this would cause a memory leak on data source restarts.
Merge pull request #2354 from chrisvest/2.0-merge-1.9

2.0 merge 1.9
Include javadocs with the manual.
Merge pull request #2357 from nawroth/javadocs

Include javadocs with the manual.
Properly closes XaLogicalLog at tests end
Merge branch '1.9-maint' into 2.0-maint

Conflicts:
	community/kernel/src/test/java/org/neo4j/kernel/impl/transaction/xaframework/XaLogicalLogTest.java
Merge pull request #2340 from rickardoberg/optimizelogging3

Optimize logging and HTTP filter
Merge pull request #2356 from jakewins/2.0-leak

Fix memory leak in DiskLayer
Merge pull request #2353 from digitalstain/1.9-maint

Changes ClusterSettings.server_id to be an InstanceId instead of an integer
Add UNWIND to the browser
Introduce QueryPlan that combines a logical plan together with a query graph