+str #15218 Add mapFuture operator
=pro in akka-docs(-dev) watch *.rst sources
Merge pull request #15325 from spray/w/add-docs-watches

add watchSources for `*.rst` files
Merge pull request #15281 from akka/wip-15218-mapFuture-patriknw

+str #15218 Add mapFuture operator
=str #15353 propagate error if TimerTransformer.onTimer throws exception
+str #15288 Add user support for Producer backed by an actor
Merge pull request #15297 from akka/wip-15288-actor-producer-patriknw

+str #15288 Add user support for Producer backed by an actor
=str #15355: fix race with ExposedPublisher messaage in tee

 - this change makes the secondary subscription lazy
=pro #15070 link to release-2.3-dev from ScalaDoc
Merge pull request #15372 from akka/wip-15070-scaladoc-link-∂π

=pro #15070 link to release-2.3-dev from ScalaDoc
scalariform ActorProducer
Merge pull request #15354 from spray/w/fix-15353

=str propagate error if TimerTransformer.onTimer throws exception, fixes #15353
=str #15347 in `concat` propagate errors in secondary upstream properly
Merge pull request #15386 from spray/w/fix-15347

=str #15347 in `concat` propagate errors in secondary upstream properly
=str Improve `merge` signature
+par Add new `akka-parsing` module with embedded copy of shapeless 2.0.0 and parboiled 2.0.0-RC2

shapeless: https://github.com/milessabin/shapeless/tree/2b34dc0f6ef134722afc2d0e98f4515383869f43
parboiled2: https://github.com/sirthias/parboiled2/tree/e25a799ea4b6a93921a028f4be2e205d1a0215e9

The only changes made are the ones required for embedding. No strip-down yet.
+hco Add `akka-http-core` module with initial HTTP model
+hco Add low-level server and (partial) client infrastructure
Merge pull request #15356 from spray/release-2.3-dev-http

akka-http-core
=hco,str small cleanups