Joining cluster member uses atomic broadcast after voting
Attach cause to ComException on Client.start

This is to enable more investigation of a rare flaky failure of IndexOperationsIT.
Fix race in IndexLookupTest with getting the test index online
Revert "Lock-free loading of relationships"

This reverts commit 7bb2861dee3d0018a4e75c84841c8b71f818d6b9.
Merge pull request #3561 from chrisvest/2.2-fix-indexlookuptest-flakiness

Fix race in IndexLookupTest with getting the test index online
Merge pull request #3555 from lutovich/2.2-rare-cluster-join-issue

Rare cluster join issue
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.
Merge pull request #3567 from chrisvest/2.2-import-empty-files

Cope better when asking import-tool to import empty files
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.
Added BidirectionalExpand as a ronja replacement for BidirectionalTraversalMatcher.
Reverted previous revert and put varlength back again.
WIP this needs to be squashed
Efficiency improvements to PathImpl
DFS! Yay!
Rename to DepthFirstExpander
Changed so that DepthExpander returns Paths