Log Message:
Update squid package to 2.5.7nb2.

* Apply official three patches.

  - 2004-12-08 01:03 (Minor) cachemgr vm_objects segfault
  - 2004-12-08 00:47 (Minor) httpd_accel_port 0 (virtual) not working correctly
  - 2004-12-07 23:45 (Cosmetic / Minor Security issue) Random error messages
		     in response to malformed host name

* use VARBASE for data directory.
* better handling data directory and user and group for squid with
  bsd.pkg.install.mk.