fetch current user model once

It could be fetched twice, I think, although it looks like Backbone
doesn't allow two fetch requests to run at the same time, so it was ok
anyway.
show "your email is not confirmed" message

http://play-perl.org/quest/511e5c7569071bae68000013
improve "your email is not confirmed" message
backend: don't lose confirmation key on updating non-email settings
various user settings improvements

error handling
ajax loading icon
etc.