[Evolution] Evo disconnects from Gmail

[Patrick O'Callaghan <poc usb ve>]

I've just reported this to BZ: 571460
Since it's short, I'll take the liberty of copying the text here:

I use the Gmail IMAP service, which usually works well. However from time
to time the mailbox becomes unavailable, I assume due to the fact that Gmail is a
"cloud" service and isn't tied to a single physical server. If I quit and
restart Evo the connection is always re-established, so it would be feasible
for Evo to simply attempt to re-open the connection by itself without needing
to be told. If one or two retries don't work, then it's an error. Since I
notice Evo already does ping servers occasionally, this wouldn't appear to be
difficult to implement.

poc