Ensure we get back correctly formatted version from server

If you are using http (not https) and if there is a captive portal or a non-auth'd proxy between us and the server, you might an unexpected reponse back from /Version or from starting the Messenger. Instead of just picking the fourth word as the version string (!) we use a more precise regex (indeed there was a todo in the code for this).

Finally, refactor the code to dedupe this stuff.