We (will) collect data in unlocked per workerthread accumulators
and whenever the workerthread leaves the session, we charge the
bill to the srcaddr (issuing a StatAddr shmrecord), to the session
and to the global counters in the stats struct.

When sessions die we issue a StatSess shmrecord.

StatAddr and StatSess has the same format:
	address
	port (always zero for StatAddr)
	duration (seconds)
	#sessions
	#requests
	#pipe
	#pass
	#fetch
	#hdrbytes
	#bodybytes



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@564 d4fa192b-c00b-0410-8231-f00ffab90ce4