nasty synchronization bits of streaming.

If there is a need, we'll bring it back as a VMOD.

Also removed some redundant stuff.

get penalized by the backend fetch.

Rough edges are to be expected, including that I had to disable
three Saint-mode test-cases, until I figure out how saint-mode should
work in this scenario.

the req workspace un-reserved before we can call vcl_lookup{} and
we can't tell if we need the predictive Vary: until vcl_lookup{}
tells us.

The missing handler would end the object spec prematurily, hiding the
rest of the methods.

Fixes: #1332

pointer as the first element.

Fixes: #1287

Spotted by:	Federico Schwindt

where the rest of the compiler can get at it.

Make it clearer that vcl_hash is called on lookup, pass and pipe.

This does absolutely not stand for "suckaddr", and but it tries to
sanitize the sockaddr_* mess enough that we can simply pass around
struct sockaddr_storage without also tracking its length.

The cost is that we do know something about address families (IPv4, IPv6),
which strictly speaking should not be necessary, had the sockaddr
not been messed up by the IPv6 people.

Add a few macros that are useful when writing vmods.