• The main change this time is the introduction of handlers to drive the
  processing of requests in LWP::UserAgent. You can also register your
  own handlers for modifying and processing requests or responses on their
  way, which I think is a much more flexible approach that trying to
  subclass LWP::UserAgent to customize it. If we have had these early on
  then the LWP::UserAgent API could have been so much simpler as the
  effect of most current attributes can easily be set up with trivial
  handlers.
  
• Also thanks to contributions by Bron Gondwana LWP's Basic/Digest auth
  modules now registers handlers which allow them to automatically fill
  in the Authorization headers without first taking the round-trip of a
  401 response when LWP knows the credentials for a given realm.
  
• We don't need to build the docs to run the tests.
  
• Style tweaks.
  
• The jigsaw service isn't up to much good these days.
  
• HTTP::Cookies produces warnings for undefined cookie param names [RT#38480]
  
• Typo fix; HTTP::Message will never include x-bzip2 in Accept-Encoding [RT#38617]
  
• Added HTTP::Config module
  
• Add methods to configure processing handlers.
  
• 100 Continue response not complete.
  
• Use 3-arg open when response content to files.
  
• Make the show_progress attribute official (by documenting it).
  
• Start using handlers for driving the inner logic of LWP::UserAgent.
  
• Expose the content_is_html and content_is_xhtml methods from HTTP::Headers.
  
• Make credentials method able to get/set values.
  
• An auth handler per realm.
  
• Match proxy setting for request.
  
• Set up separate handler for adding proxy authentication.
  
• Add request_preprepare to be able to initialize proxy early enough.
  
• Smarter get_my_handler() that can also create handlers.
  
• Refactor; introduce run_handlers method
  
• Pass in handler hash to the handler callback.
  
• Don't let version=1 override behaviour if specified with a plan Set-Cookie header.
  
• Remove handler when we don't have a username/password for the realm.
  
• Make tests use Test.pm
  
• Double-check that username or password has changed after a failed login.
  
• Update Digest Authen to subclass Basic.
  
• Avoid running out of filehandles with DYNAMIC_FILE_UPLOAD.
  
• Fixed parsing of header values starting with ':' [RT#39367]
  
• Documentation typo fixes [RT#38203]