rather than saving the entire thing.

This also moves a bit more of the fetch-policy/standards-compliance into
rfc2616.c

accordingly.

initialize struct exp, and use it.

Pass an 'exp' instead of just the ttl to STV_NewObject()

Have -spersistent always use the graced timeout for object index,
rearm when we resurrect the zombie object.

in cache_expire.c

All this interior decoration should make it less painful to add
yet a timer for IMS processing.

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.