Order labels, relationships and property keys in drawer.
Add `:help history` command and frame.
Update :help start information.
Add more tests to ensure the interaction between TransactionEventHandlers and indexes

This verifies that github issues #3590, #2851, #2270 and #2714 are fixed in 2.2.
Unignore varlength tests
Refactoring of how logical plans for expanding into an existing identifier is handled
Fixes cardinality estimation problems around LIMIT
Reenable ignored cypher index usage acceptance test
Merge pull request #3580 from systay/expand-plan-refactoring

Expand plan refactoring
Merge pull request #3599 from systay/limit-cardinality

Fixes cardinality estimation problems around LIMIT
Merge pull request #3600 from davidegrohmann/2.2-reenable-test

Reenable ignored cypher index usage acceptance test
Fix parent in neo4j-harness.
Update references to docs.neo4j.org to point to neo4j.com/docs.
Introducing GraphDatabaseService.execute(...)

Enables executing cypher queries without having to keep track of an
ExecutionEngine instance, instead the database keeps the ExecutionEngine
internally.
Unignored tests in Cypher.

Mostly just unignoring tests, but some small fixes to get green.
Update semantic table as part of identifier namespacing
Merge pull request #3410 from thobe/2.2-gds-execute

Introducing GraphDatabaseService.execute(...)
Merge pull request #3603 from pontusmelke/unignoring-tests

Unignored tests in Cypher.
Unignored test in Cypher.
Fix flaky test in TransactionIT closing socket to terminate transaction.

The test will now allow some time for the socket closing to propagate
network stacks and actually have an effect. It is a speculative fix.