Update csv location; clean up docs.neo4j.org references.
Attach cause to ComException on Client.start

This is to enable more investigation of a rare flaky failure of IndexOperationsIT.
DumpLogicalLog: Output format version.

This is crucial for debugging.
Revert "Debug logging of cluster members state"

This reverts commit 89f93d3c986efe18574bb353453195893f8f0b9e.
Cope better when asking import-tool to import empty files

* ImportTool now no longer prints a big stack trace (by default) when asked to import empty files.
* Add a new --stacktrace command line option that can enable printing of stack
  traces for those who want to debug things.
* The Thread created by the ThreadReadaheadReadable has been made daemon so it
  no longer prevents a shut down of the importer process.
* Panics in the import pipeline now preserve exception messages when wrapping
  causes.
Fix broken link to Neo4j.rb.
Merge pull request #3567 from chrisvest/2.2-import-empty-files

Cope better when asking import-tool to import empty files
Reintroduce automatic entity removal for legacy indexes
Add missing entry for import in manpage list.
Merge pull request #3559 from chrisvest/2.2-indexops-it

Attach cause to ComException on Client.start
Merge pull request #3566 from lutovich/2.2-remove-debug-logging

Revert "Debug logging of cluster members state"
Merge pull request #3572 from nawroth/import-manpage

Add missing entry for import in manpage list.
Revert "Revert "Lock-free loading of relationships""

This reverts commit 11913455f8cbab4d601e72b4d4d3f08095e3e6ed.

I.e. it's a re-revert, hence a re-commit of
7bb2861dee3d0018a4e75c84841c8b71f818d6b9
Update fingerprint if plan is still valid

We have three guards in place for replanning:

1. How much time has passed since the query was planned?
2. How many transactions have been committed since the query was planned?
3. How much has the statistics changed since the query was planned?

These guards are ordered the way they are since it is assumed that the
later guards are more expensive than the former guards. Going to the
store for the current transaction ID is more expensive than looking at
the current time, and going to the store for several statistical
values is more expensive than just getting a single transaction id.

This has a problem in that after a guard has first failed, it will
continue to fail even if the later guards still keep the query
alive. Say that the database is very read heavy, so after the default
query TTL of 1 second has passed, guard (1) will always say that the
query needs to be re-planned. This means that we will always go to
disk to read the transaction ID, making each execution of the query
more expensive.

This commit solves this by updating the guards that say "replan" if a
later guard says not to replan. I.e. we should update the timestamp
for a query if we find that we have not seen that many transactions.
Make sure to start the standalone page cache
Merge pull request #3579 from chrisvest/2.2-fix-standalone-pagecache

Make sure to start the standalone page cache
Introducing TripletQueryGraphCardinalityModel
Draft of VarLengthTripletCardinalityEstimator
Removed multi-threaded CC, fixed duplicated errors in multi-pass CC
Minor cleanup in neo4j-server.properties