Lower memory overhead of recordchanges.changeCount()
Fix shadowing issues with aggregation in Ronja

Signed-off-by: Stefan Plantikow <stefan.plantikow@neotechnology.com>
Fix: Correctly isolate aggregates from expressions that introduce interior scopes (reduce, fitler, extract, comprehensions)

signed-off-by: Jakub Wieczorek <jakub.wieczorek@neotechnology.com>
Merge pull request #2717 from jakub-/ronja-aggregation

Fix shadowing issues with aggregation in Ronja
Merge pull request #2720 from boggle/2.1-maint

Fix: Correctly isolate aggregates from expressions that introduce interi...
Do not check relationship uniqueness for relationships with different types

signed-off-by: Jakub Wieczorek <jakub.wieczorek@neotechnology.com>
Merge pull request #2723 from boggle/2.1-maint

Do not check relationship uniqueness for relationships with different ty...
Merge pull request #2724 from neo4j/2.1-maint

2.1 maint -> master
Central transaction repository

Introduces a central component through which transactions are accessible,
"KernelTransactions". This is then used to force-stop running transactions
on database shutdown.

Also introduces usage of the new Marshland pool for transactions. This removes
the usage of two lower-level pools (record changes and lock clients), as those
components will now be tied to a transaction instance for the full lifecycle
of the database.
Merge pull request #2707 from jakewins/2.2-kiltx

Central transaction repository
Added missing test to KernelTransactions, removed accidentally committed perftest