- watch server going offline, reset database meta-information when it come back online
- revise legend to only display labels displayed in graph
Test compatibility reading from old index format.

Index format has subtly changed since 2.0.0
(numbers are written as string fields instead of numeric fields,
but using the same numeric format).
This test confirms that new code can read the old format.
Updated rolling upgrade 'quick verification' IT test so that it can be used again

(cherry picked from commit 3636952ae2c5d89bf4d3e9917ec3cacca774e103)

Conflicts:
	enterprise/ha/src/test/java/org/neo4j/ha/upgrade/RollingUpgradeIT.java

Fixed some issues with the test itself

(cherry picked from commit 6d5aed4d27520bdb0179356aedf29a8abc05cad3)
Ties each NeoStoreTransaction to the transaction state object

instead of in a shared (and synchronized) ArrayMap to completely remove
that contention point. It's not an optimal place for those objects, but
it's temporary fix at least.
Merge pull request #1748 from akollegger/browser-resync

Fix sidebar and legend tracking of graph labels
Merge pull request #1836 from tinwelint/2.0-no-persmgr-map-contention

Ties each NeoStoreTransaction to the transaction state object
Merge pull request #1798 from apcj/index-compat

Test compatibility reading from old index format.