[PATCH] Port 2.7: logformat %oa

Well sort of...

This adds the log format to log the local IP address used on outgoing
connections to peers and servers. Squid-2.7 called this %oa.

However it is a perfectly matching part of the existing set of %la and
%lp (local inbound) and %<lp (local outbound port).

As such, the %oa is accepted as input for backward compatibility, but
the Squid-3 version is: %<la

This is based only very loosely on the Squid-2 %oa work by Andrew Atangulov

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.11
   Beta testers wanted for 3.2.0.5