Document EFA->stop and EFA->stops

Returns a list of B<place> candidates if I<place> is ambiguous. Returns

nothing (undef / empty list) otherwise.

=item $status->stop

Returns a Travel::Status::DE::EFA::Stop(3pm) instance describing the requested

stop.

=item $status->stops

In case the requested place/name is served by multiple stops and the backend

provides a list of those: returns a list of Travel::Status::DE::EFA::Stop(3pm)

instances describing each of them. Returns an empty list otherwise.

=item $status->results

Returns a list of Travel::Status::DE::EFA::Departure(3pm) objects, each one describing