Rename the fallback-users entry to wildcard-user, and only
allow a single fallback user.  This is missing the HTTP API.

Suggested by Dianne Skoll.

This avoids displaying "internal server error" when a username
is disabled.

Double-click, because otherwise it interferes with selection.

Otherwise warning messages during upgrading cannot print the
filename.

We used to return nil, nil if the token didn't exist.
We now return os.ErrNotExist.

Signed-off-by: Sebastien Binet <binet@cern.ch>

We used to test AutoSubgroups before upgrading the description,
which would break handling of the (obsolete) AllowSubgroups
field.

Thanks to David Saulpic.

This avoids a crash in the VP8 parser.

The former don't properly unwrap errors.

We now create the server and the listener in the calling thread,
and only create a new goroutine before calling server.Serve.

The previous way depended on implementation details
of GetConfiguration.