Ensure that all Cypher 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.
Fix tests that would be slowed by transaction leakage.

There are still about 18 tests that leak transactions, but those do so in a way
that it will not cause slow downs, I think.
Remove constraint indexes if data is not unique.

When failing to create a unique index for a uniqueness constraint, the
index should be dropped immediately.

Fixes mistakes made in ConstraintIndexCreator in
e1e3b987343a0df878d6beda76a1b09c6330f7f1 where the index was no longer
removed if creation failed, and in its tests in
718635a384820e98853609499116e17482a99b85 where the test did no longer
assert this behaviour.

Fixes #1492.
Update the Enterprise CacheProvider configuration point to the renamed HighPerformanceCacheProvider.
Update server installation instructions for os x based on acceptance
Merge pull request #1490 from chrisvest/2.0-unclosed-txn-tests

Fix tests that would be slowed by transaction leakage.
Merge pull request #1495 from thobe/2.0-remove-failed-constraint-index

Remove constraint indexes if data is not unique.
Cleanup of haversin example. Added note on syntax change re optional rels.
Unused imports.
Updated CHANGES.txt with the GCR to HPC rename.
Merge pull request #1496 from jakewins/fix-slipup-in-renaming-gcr-to-hpc

Fix slipup in renaming gcr to hpc
Include browser in the regular build.
Revert "Include browser in the regular build."

This reverts commit f8e12775eefc4d45c164c8f0cb462efc532e5dac.
Refactoring of optional match