Solaris, (remember Solaris?) will return connection related errnos
on fd metadata operations such as ioctl(2), [gs]etsockopt(2) etc.

We propagated these errors up from VTC_(non)blocking() which could,
theoretically, bail out earlier than it would otherwise have done.
This complicated code far more than it speeded anything up.

Instead just ensure that any errors returned are indeed connection
related, and then ignore them, and let Solaris deal with the broken
connection same way as other operating systems.

Conflicts:
	bin/varnishd/cache/cache_req_fsm.c
	include/tbl/vsl_tags.h

Other SLTs were back-ported as well, but marked as not supported, to
ensure binary forward compatibility up to 6.2 releases.

And we have a goal of making the VSL self-documenting so reordering
anything is pointless. We already reorder SLTs in the documentation
where sorting really matters to end users.

When a VMOD returns a STRANDS, it is a requirement that the storage
be stable, but that is not really different from any other type of
return value.

Completes #2873

Strenghen the case against STRING_LIST in the docs.

See also: #2873

Conflicts:
	lib/libvmod_debug/vmod.vcc

Conflicts:
	lib/libvmod_blob/hex.c

Re-implementations of the current functions for STRING_LIST.

Closes #2733

Conflicts:
	include/vrt.h
	lib/libvmod_debug/vmod.vcc
	lib/libvmod_debug/vmod_debug.c

This introduces VRT 7.1 for the 6.0 releases.

Fixes #2846

Fixes #2880

Fixes #2879

This has bugged me (slightly) for ages.

Too trivial to warrant its own line(s) in test-case/u00008.vtc.

Should address "HTTP cache must not reuse a response with an invalid
Cache-Control: max-age (trailing alpha)" from https://cache-tests.fyi.

Should address "HTTP cache must not use a cached response with
Cache-Control: No-CaChE, even with max-age and Expires" from
https://cache-tests.fyi.

Fixes: #2874

Fixes #2871.

Conflicts:
	bin/varnishd/cache/cache_fetch.c

Submitted by:   Frederic Lecaille <flecaille@haproxy.com>

It turns out people are really attached to their varnish.params file.