It's a loose comparison of socket addresses, not including the port
number. But not loose enough to compare IPv4 addresses to v4-mapped
IPv6 addresses.

Fixes #2142

Adapted from an original patch from @michbsd: on top of normalizing the
host header we now have a regular expressions that only match the right
domains and potential sub-domains.

Closes #2140

This should stabilize c00049

Previously, unless HAVE_TCP_KEEP was defined equally for varnishd
and an API client (vmod), the latter used a wrong struct declaration
and, consequently, struct params members were accessed at a wrong
location. This could have adverse effects from reading bogus
values to overwriting wrong parameters or other memory.

For consistency, we keep uninplemented parameters also in the
cli and rst output with an appropriate description.

Setting them over the cli is not an error, but has no effect.

is no longer around.

Fixes #2148.

correct course of action is.

Spotted by VTEST

They live as private macros in varnish.m4, which is now included in the
Varnish build during the autogen phase. This way it is now possible to
dogfood on macros we distribute downstream. Considering how simple they
are, they could be made public macros for the convenience of VMOD or VUT
writers.

We don't need to have the LIBS-saving-dance in configure.ac for every
single dependency.

There is now similar logic in varnishd, but by then it may be
too late already, but that still improves chances for the users.

We don't need AC_PROG_CPP, because we don't use the C preprocessor
standalone for anything.

It's not obvious that anybody needs AC_PROG_MAKE_SET ever, it looks
like a band-aid for some crappy Win98-related tinker-toy-compiler.

Amazing (or not...) that nobody in the autocrap community ever
got the idea to add "What made AC_FOOBAR necessary" explanations
to their documentation or changelogs.

This should stabilize r00962 on Ubuntu and make -spersistent less
useless on same.

Should the minimum be bumped from 9k to 12k?

This goes into the 'id' on the server side, and is necessary because
certain distingushing facts, like compiler/target architecture,
cannot be determined until after autogen and the configure it
creates have been run.

This should make distcheck happy on SmartOS