If the connection is being established, the key with a clock icon is
shown.
If the connection has been established, the key without the clock icon
is shown.

I've also added all some icons to more resolutions.

I've also fixed another message: if a file to be downloaded is not
found, we say the entered provider isn't a LEAP provider. This is based
on the fact that if provider.json doesn't exist/contain valid
information, then the url isn't pointing to a LEAP provider.