Fix bug in summarizing stats

Stats were not being summarized even if it was requested, if the state
and timeout were not set
Be more aggressive summarizing stats

Remove pipeline stats, since they're unused
Make parsing of taskId parts lazy
Fix IntelliJ warning
Add release notes for 0.84
[maven-release-plugin] prepare release 0.84
[maven-release-plugin] prepare for next development iteration
Replace Murmur3 with Xxhash