=tes #15165 MetricsKit should not nullpointer on racy graphite usage
The report() call can come from multiple threads in our code,
yet it was opening/closing a shared graphite client instance in this
method, causing NPE when periodic reporting kicked in during a manual
report() call. We want to be able to do this - thus rewrite to safe impl

Removed metrics-graphite dependency, replaced by in house impl.
The previous was using discrete write() calls, which could be entangled
when called from multiple threads, and produce invalid metric lines.
Current impl is simpler and threadsafe, as the lock for write(String) to
aquired for the entire string lenght's write (unlike multiple write calls).

Resolves #15165

Conflicts:
	akka-testkit/src/test/scala/akka/testkit/metrics/reporter/AkkaGraphiteReporter.scala
	project/Dependencies.scala
+scr additional functions for tagging issues on github
Merge pull request #15263 from ktoso/scr-github-tagging-pr-validator

+scr functions for tagging issues on github, for pr-validator
Merge pull request #15247 from ktoso/port-graphite-client-rewrite-metricskit-ktoso

=tes #15228 backport - metricskit fix for racy graphite client (for validation)
=act #15165 should fix out-of-bounds in actor creation
Other than that, also improved failure logging when AIOOB happens in the histogram
Added a test which shows why the updateWithExpectedInterval method
should be preferred too.

Backport from master

Conflicts:
	akka-testkit/src/test/scala/akka/testkit/metrics/reporter/AkkaGraphiteReporter.scala
=src jenkins needs explicit bash usage
Merge pull request #15266 from ktoso/jenkins-needs-bash-shebang

=scr jenkins needs to use bash, not sh
Merge pull request #15264 from ktoso/port-metrics-kit-fixes-from-master

=tes,act forward port of metricskit / test stability improvements
=pro Upgrade akka-stream dependencies to akka 2.3.3

* Upgrade dependency to akka 2.3.3
* Remove javadsl.Pair and javadsl.Predicate in favor of akka.japi.*
+str #15088, #15200: Add takeAndTail and concatAll
+ben #15064 v. simple JMH benchmark for akka streams (map, 5map)
Merge pull request #15272 from ktoso/ben-naive-stream-benchmark

=ben #15064 initial example akka-streams bench (map, 5 maps)
Merge pull request #15226 from drewhk/wip-15088-concatall-take-tail-drewhk

ConcatAll and TakeAndTail
Merge pull request #15268 from akka/wip-upgrade-stream-dependencies-to-akka-2.3.3-ban

=pro Upgrade akka-stream dependencies to akka 2.3.3
=scr silence curl on jenkins, no need for progress bars
Merge pull request #15275 from ktoso/silent-curl-for-jenkins

=scr silence curl for github tagging
+str #15081: Implement conflate, expand and buffer