* Stop appending '/api' to configured galaxy server url
Since not all galaxy REST api server URLs live
at '/api', stop always appending it to the
'url' value loaded from config.
* Add note about manually migrated galaxy configs and /api
* Add '/api/' to galaxy url and guessing if galaxy API
* Fix most unit tests (update to expect /api/)
* Fix test_initialise_unknown unit test
Since we retry now with an added /api/, mock it as well.
* Update fallback default avail_ver to new format