Better 'Verify Server' error messages

[gpittarelli]

Currently, if a user tries to create a lobby, if they enter a server that can't be reached and click 'Verify Server' they get an error message like:

dial tcp 1.2.3.4:27016: getsockopt: connection refused

These errors should be more user friendly.

[gpittarelli]

Also, if Pauling goes down for some reason, a lot of stuff goes really weird, but if its in the middle of a lobby create request, the frontend will be sent a sendNotification with "unexpected EOF"