fix: foreach in null should execute 0 times
Move acceptane of MATCH to it's own test suite
Move out agreggation into its own acceptance test class
Break out acceptance tests of RETURN into it's own class
Merge pull request #2005 from davidegrohmann/2.0-fix-foreach-null

fix "foreach in null" should execute 0 times
Fix relative path when using file://$path in LOAD CSV
Merge pull request #1981 from systay/match-acceptance

Break down ExecutionEngineTest into smaller pieces
Merge pull request #2006 from digitalstain/2.0-maint

Merge branch 1.9-maint into 2.0-maint
Fix Windows build
Fix Windows path handling in unit tests
Move status codes for Cypher exceptions to Cypher exceptions
Make ast.Query a concrete class
Remove the CleanupService

This is safe to do since we in 2.0 also require transactions for reads.
That way, we never litter outside of transactions, and so any trash that might have escaped,
is now being cleaned up along with the transaction state.
Move CSV handling to QueryContext

We want to consolidate access to the outside world
behind this facade. That makes it possible to handle
freeing of resources in QueryContext's, instead of
having multiple places remember to clean up state
after a query is finished.
Adding tests around the backup tool.

o Tests covering the following:
  o Copying of files from store -> backup
  o Transactions that happen during copy are replayed
    onto the backup store
  o A transaction log contianing the latest transaction
    for lucene & neostore is in the backup
Merge pull request #2017 from chrisvest/2.0-remove-cleanup-service

Remove the CleanupService
Merge pull request #1928 from mneedham/1.9-main-testing-backup

Adding tests around the backup tool.
Merge pull request #2019 from davidegrohmann/2.0-load-csv-query-context-refactor

Move CSV handling to QueryContext
Cypher docs update
Merge pull request #2027 from systay/2.0-docs-update

Cypher docs update