extended access logging patch

Hello

This patch implements extended access logging.
You can use "accloggran" option to tell squid when a log record has to
be put into access.log. Default value is 1024 KB (1MB) which means that
after each 1024 kB of data downloaded by client you get one entry. Also
a access.log records has been slightly modified, instead IP you get
IP:port where port is client's agent port.

Patch applies to squid2.5-stable5, to enable this feature use
--enable-extacclog with configure. Before configure you have to run
bootstrap.sh.

I'm waiting for feedback.

Regards
Michal Matusiak