manipulation is actually the relative value, not the absolute time.

HSH_Grace() to EXP_Grace()

Found & Patch by:	Dmitry Panov

in order to encapsulate the lack of of API coordination between
different OS's in this arena.

This only affects development environments on FreeBSD, but hopefully
exposing the Varnish source code to yet another compiler will help
expose bugs.

Fixes #821

previously known as purge" to ban.

The sphinx configuration includes the version number, so generate the
configuration.

Spotted by:	Geoff

The director is freed in vcc_backend.c already, so don't free it in
vcc_dir_dns.c too.

Fixes: #863

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.

it has its own parameter.

before we start setting them otherwise.