err_ttl:
	Pointless and wrongly documented.  Remove and set Retry-After:
	in default.vcl
expiry_sleep:
	Remove misleading advise.
send_timeout:
	Reduce to one minute, 10 minutes was far too long.
ban_lurker_sleep:
	Reduce sleep between successful evictions to 10msec to speed
	ban lurker up to max 100 objects/second.