This improves the internal iteration by up to a factor of 5.

It's still a bit slow, though.
Update to new artifactId cypherdoc->graphgist.
Merge pull request #2285 from chrisvest/2.1-prim-long-int-map-iteration

Speed up the internal iteration of PrimitiveLongIntHashMap
update change logs for 2.1.0-M02
Further refined approach to upgrade.
- If intermediary structure does not fit in RAM, fall back
  to a multi-pass approach.
- Make upgrade mostly GC free.
Update change logs for Cypher
Add support for SelectOrSemiApply
Merge pull request #2306 from systay/subgraph-signature

Add support for SelectOrSemiApply
Added info messages on incoming connections as well. This can help when a rogue cluster instance connects and you don't know where it is in the environment.
Merge pull request #2257 from jakewins/2.1-even-faster-upgrade

Further refined approach to upgrade.
Add support for negated pattern predicate
Merge pull request #2313 from systay/subgraph-signature

Add support for negated pattern predicate
Get rid of NotExists and HoldsOrExists
Add support for SelectOrAntiSemiApply
Merge pull request #2315 from systay/subgraph-signature

Add support for SelectOrAntiSemiApply