SERVER-SIDE PERSISTENT CONNECTIONS:

SERVER-SIDE PERSISTENT CONNECTIONS:
	- Added pconn.c
	- Addec Cofig.Timeout.pconn; default 120 seconds
	- Added httpState->flags
	- Added flags arg to httpBuildRequestHeader()
	- Added HTTP_PROXYING and HTTP_KEEPALIVE flags
	- Added 'Connection' to allowed HTTP headers (http-anon.c)
	- Added 'Proxy-Connection' to allowed HTTP headers (http-anon.c)
	- Merged proxyhttpStart() with httpStart() and crated new
	  httpBuildState().
	- New httpPconnTransferDone() detects end-of-data on persistent
	  connections.

Other casualties:
	- clean up casting of HASHCMP functions
	- changed comm_open to return -1 instead of wierd COMM_ERROR
	- cbdata-ify comm_close_handler stuff
	- make some args const
	- changed some PARAMS(()) to CNCB's
	- Fixed cachemgrShutdown() not being used