!str #16166 upgrade stream TCP APIs to end-user style
!htc #16162 upgrade HTTP-level APIs to end-user style
!htp upgrade (and simplify) main API entrypoints
=str apply review feedback
+htc add `startHandlingWith*` helper methods to `Http.ServerBinding` and `Http.IncomingConnection`
!htp remove `ScalaRoutingDSL`
Merge pull request #16414 from spray/wip-16162-mathias

!htp #16162 Upgrade server- and client-side HTTP APIs to "final style"