Author: Guido Serassio <guido.serassio@acmeconsulting.it>

Author: Guido Serassio <guido.serassio@acmeconsulting.it>
Removed unused ICAPClientStream code.

The functions provided by ICAP/ICAPClientStream.{cc,h} were called from
client_side_reply.cc but the code was #ifdef-ed with
ICAP_CLIENT_RESPMOD_POSTCACHE, which was not defined anywhere. Somebody was
either trying to get ICAP RESPMOD post-cache work with client streams long
time ago (but did not get far) or just wanted to provide hooks for future use.