COSS removal from Squid-3

COSS removal from Squid-3

I'm expanding the COSS 'removal' from just 3.0 to all Squid-3.
The hoped for work has not yet been presented. When someone is available
they need to revert this patch. - Amos

  We had a vote on this some (several) months before 3.0 got branched, and
  it was decided to drop COSS from the Squid-3.0 branch once branched.
  Then the branching got delayed, and this task was forgotten when it
  finally branched.

  Until COSS gets significantly updated it's counter-productive to ship it
  in STABLE releases. But the current code needs to be kept in trunk as
  reference on how things got refactored for the day the current COSS code
  gets forward ported to Squid-3.

  Regards
  Henrik