Make HA fail to start with old store
Improved code for moving migrated files in the store directory
Make slave fail when master have different upgraded store
Improve description of data integrity in manual
StoreId contains upgrade info and is broadcasted to the whole cluster, slave checks all StoreIds on startup
Merge pull request #2942 from cleishm/data-integrity-docs

Improve description of data integrity in manual
Merge pull request #2930 from davidegrohmann/2.1-store-migration-cleanup

Improved code for moving migrated files in the store directory
Improve performance of index lookup with tx state.

Performing an index lookup in a transaction with state was implemented
as a linear scan over the transaction state. Even if the lookup from the
underlying store was fast, the performance would degrade linearly to the
size of the active transaction.
This change set improves the performance of index lookups in a
transaction in a transaction with state by building up an index-like
structure in the transaction state as well. This index state is built
for the indexes defined by the schema.
Fixes race condition in test code.

RemoteRequestMonitoringIT would fail under certain cicrumstances
due to EideticRequestMonitor not being thread safe.

This diff also improves the failure reporting on the same test case.
Merge pull request #2966 from thobe/2.1-index-tx-state

[2.1] Improve performance of index lookup with tx state.
Add suppot for migrating logs from 2.0 to 2.1

- some code cleanup and refactors
Javadoced TransactionMonitor so it is clearer what it monitors
Removed usage of TransactionMonitor from HA processes. It is local only.
Merge pull request #2967 from davidegrohmann/2.1-migrate-logs-from-2.0

[2.1] Add support for migrating logs from 2.0 to 2.1
Set node caption to first attribute if no style.

If no grass style that match a node with
attributes specifies which caption to use,
the first one from the attribute list will be
chosen. If no attributes, db id it is.
Remove variable check that's always true.
Moves ParallelBatchImportTest into consistency-check for added checks
Test case for race with commit updating the cache.

When a transaction commits, it will update nodes in the (object) cache
to add relationships to them that were created by the transaction. It is
however possible that the node was not in cache when the transaction
started its commit process, but was put into the cache by another thread
reading the relationships of that node. If this other thread read the
relationships after the committing transaction had written them to the
store, but before it updated the cache, the reading thread would have
already read the relationships that the committing transaction is about
to add into the cache. If that happens, the committing transaction will
still add these relationships, but now they will be in the cache twice
for that node.
Fix for race with commit updating the cache.

Extends the range of the locks acquired while writing to the store, to a
greater region including the place where we update the cache. Also make
sure we acquire corresponding read locks when attempting to read
relationships into the cache for a node.

This should be deadlock free because reader threads only ever acquire
a lock for one node at a time, and release it immediately after updating
that node. And while the writer thread acquires multiple locks, we only
ever have one writer thread acquiring locks at any given time.
Disables IoQueue temporarily from the batch importer
Actually enables it for tests