BUGFIX: in_memory_ticket_store missing Headers import.
Option `verify_cert` made available for in_memory_ticket_store.
Experimental bugfixes.
Merge branch 'local_27' into bugfix
BUGFIX: Properly escape service URL parameters (don't just tack on the ticket).

Also, issue a WARN log entry if the service URL already contained a `ticket`, as this could potentially
be someone up to no good.
BUGFIX: URL query string parameters are `parsed.query` *not* `parsed.params`.

URL params are acutally rarely used parts of the URL:

  https://www.example.com/path/to/resource;param1=foo;param2=baz?qsparam=thing
                                          ^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^
                                          parameters             query string