Final tweaks to live test of third-party registration interface
Code review markups: extracting a utility function, testing an unregister, changing 'raise' to 'fail'
Documentation of EXPIRES option; more rigorous testing of implicit registration
Merge pull request #21 from Metaswitch/registrar_test

Live test of third-party registration
Merge branch 'master' into quaffify-b2bua
Fixes to B2BUA ISC test