Make ronja pipes avoid unnecessary copies of execution context maps
Refactor IdSeekIterator
Increase the test timeout for PageCacheTest#rewind…
Remove the StandardPageCache and make Muninn the default
Reduce the memory overhead of the MuninnPageCache

Every instance of a class that overrides the `finalize` method, gets a ~40-byte
companion `java.lang.ref.Finalizer` object, that uses the reference mechanism
to track the lifetime of the object and run the finalizer when needed.

These Finalizer objects also participate in a JVM-wide doubly-linked list,
which worsens the GC pause times.

These issues have been fixed by introducing a MemoryReleaser that knows about
all the raw pointers that we will want to release, and then every MuninnPage
has a reference to the MemoryReleaser. When all the pages have been collected,
the MemoryReleaser becomes elegible for finalization, and then it will free
all our pointers in bulk in its finalizer method.
Avoid object creation in Pipes
Make community tests pass with the MuninnPageCache

... without running out of memory
Merge pull request #3089 from chrisvest/2.2-pc-rewind-timeout

Increase the test timeout for PageCacheTest#rewind…
Add a timeout on the failedLatch which waits for the master to disappear

- removed the electedLatch since we can use cluster.await instead
Merge pull request #3087 from boggle/micro-ops

Cypher performance optimizations
Merge pull request #3086 from chrisvest/2.2-muninn-ftw

2.2 Make Muninn the One True PageCache
Completes the IdMapper interface change

by letting InputRelationship deal with Object ids for start/end nodes.
Now it became apparent that stages 1 and 2 cannot be executed in parallel
if the IdMapper needs preparation. Put that check in and added comments
about it.
Merge branch '2.1-maint'

Conflicts:
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/RelationshipEncoderStep.java
	community/neo4j/src/test/java/upgrade/StoreUpgraderTest.java
Fixes a license header
Merge branch '2.1-maint'
Evict from cache as late as possible in race test.
Exact number of relationships given node label.

The CountsStore maintains the exact number of relationships in the
database that either starts or ends in a node with a given label. Counts
are maintained both in total, and by relationship type, but only for one
label, i.e. number of relationships that starts in a node with a given
label and ends in a node with a given label is not maintained.
Fix an issue reading transaction logs over network.

NetworkReadableLogChannel should not check if there is enough data available before reading.
Netty will throw an IndexOutOfBoundsException if the network stream doesn't supply enough data
to match the requested type.

ReadPastEndException was refactored as a singleton without stack trace as it is a common and
expected case in the code paths.

Also removed some logging previously added for debugging this issue.
Merge pull request #3092 from davidegrohmann/2.2-avoid-unboud-wait

Add a timeout on the failedLatch which waits for the master to disappear
Merge pull request #3094 from thobe/2.2-counts-store

Number of relationships given node label.