Revert "[Reviewer Andy] Don't hairpin outgoing requests"
Merge pull request #717 from Metaswitch/revert-705-issue704

Revert "[Reviewer Andy] Don't hairpin outgoing requests"
Don't log to SAS until we've parsed information out of the JSON; defend against null pointers.
Bring SAS REGISTER logging function in handlers into UT
Add test covering an IMPU that can't be parsed as a SIP URI
Merge pull request #718 from Metaswitch/handlers_crash

[Reviewer: Matt] Fix crash in AuthTimeoutHandler
Change Metaswitch submodule refs to ClearwaterCore