Add missing code for closing the pageCache when used in migration/tools
Move the adversarial file system to the io module
Add a robustness test for the page caches

It uses the adversarial file system to throw lots of exceptions at the page cache implementations.
It currently fails. Badly.
Make the MuninnPageCache survive the adversarial file system

* Fix a bug in the AdversarialFSA where mischief might prevent client code from
  ever reading the last byte of a chunk into a buffer.
* The Muninn eviction thread now no longer dies if flushing on eviction throws
  an exception.
* This makes Muninn able to recover from arbitrary errors, should their cause
  disappear.
AdversarialFSA PageCacheTest

Increase failure probabilities and fix some of the failures in the StandardPageCache.
Not all of the failures are fixed, though, so the test is still failing.
It has therefore been ignored for now, because we want to get the fixes for Muninn into master as soon as possible.
Add parens to documented cypher queries
Merge pull request #3066 from cleishm/cypher-doc-parens

[2.1] Add parens to documented cypher queries
Merge pull request #3070 from chrisvest/2.2-pc-robustness

2.2 PageCache robustness test based on the adversarial file system
Merge remote-tracking branch 'upstream/2.1-maint'

* upstream/2.1-maint:
  Add parens to documented cypher queries
Merge pull request #3052 from davidegrohmann/2.2-close-page-cache

Add missing code for closing the pageCache when used in migration/tools
Add a cardinality estimator based on the query graph

Signed-off-by: Jakub Wieczorek <jakub@jakub.cc>
Add QueriedGraphStatistics that collect statistics using core API at runtime
Hook in the QueriedGraphStatistics
Minor fixes to cardinality estimation and friends
Mark all pipes being used by Ronja with a trait to identify them
Add estimated rows to all Ronja execution plans