Options page does not report request progress

[rasendubi]

Problem: when logging in, the options dialog does not report any progress. It's just saying "You are not logged in," so it's hard to tell if I got my username/password wrong or it's Heroku starting up the server, so it is responding slowly (or not responding at all).

Possible solutions:

1. Add a spinner, so I can tell if the request is in progress.
2. Report response status (like "you're logged in as ", or "there is no user with such username and password", or "can't contact the server")

[drets]

It would be cool to add the second point (“Report response status”) to front repo too.

[drets]

ping @rasendubi

[rasendubi]

It would be good to improve error messages, but this issue is solved.