Patch for login exchange timeout

[micbowman at comcast.net]

I agree with select/timeout. This was a *fast*, minimal impact to the current code kind of patch. Change it however you want.

--Mic

> Mic Bowman wrote:
> > Here's a quick patch that adds a timeout (value set
> > from the connection timeout config parameter) for
> > identification exchange. 
> 
> I think the idea is ok, but IMO the implementation should do
> select+timeout rather than use signals.
> 
> Also, maybe the timeout for the banner exchange should be
> ConnectionTimeout less the time actually used during the connect phase.
> 
> -d