fix the signature of Strict-Transport-Security header #19861
parse strict-transport-security header with the max-age directive only #19861
parse includeSubDomains directive #19861
add doc on Stict-Transport-Security #19861
fix punctuation in doc on Stict-Transport-Security #19861
* Re enabling Java tests in akka-docs (they were not run before)
* Fixed bug #19764
* #19735 Rewrote every sample using the deprecated PushPullStage and friends
using GraphStage
* Pruned old unused graph images
* Added missing graffle file for new graph images