Socket errors

[Sean Egan]

I'm thinking of how to better special case connection errors in the UI
now that resiak has given us that opportunity.

Right now, the only error we special case is "You've logged in
elsewhere." We have just a single pane in the buddy list that says
"These accounts were disconnected because you signed on elsewhere" and
a "Re-enable" button. This solves the case where I would be logged
into Pidgin at home, go to work, log in there, come home and have to
click 20 different buttons to restore everything. Now everything goes
back to normal with one click.

The most common connection error is
PURPLE_CONNECTION_ERROR_NETWORK_ERROR, or "you were randomly
disconnected for no particular reason."

I'd like to combine all these into a single connection error dialog,
"The following connections were disconnected. Reconnecting in XX
seconds" with a "Reconnect now" button to force the matter. This also
implies combining our current auto-reconnect behavior into a single
unified reconnect mechanism (which probably makes sense, as if more
than one account is randomly disconnected, they'll probably all be
able to come back online at the same time).

Sound good?

-s.