Refs #159

There is no --disable-jemalloc, or at least not anymore.

RPM macros for systemd used to be part of the main systemd package but
on Fedora they moved to their own subpackage. The %{systemd_requires}
macro is no longer guaranteed to be present in a default build root.

This change enables Fedora Rawhide builds, for a current Rawhide target
of Fedora 36.

Closes #153

This will match the default hitch configuration, making interaction
between it and varnish easier.

Otherwise host resolution may not be available during boot resulting in
startup failure of varnish.service for no good reason.

weekly is now dead, we use master for weeklies now

There is only python2 and python3 packages

to avoid unnecessary errors when running outside jenkins

Starting with el8 annobin is used to annotate ELF binaries and this is
set up via the %configure RPM macro. As a result annobin becomes a
requirement of the default cc_command in varnishd but it relies on GCC
spec files that are provided by redhat-rpm-config.

So, similar to how we explicitly require GCC at run time we now also
need to bring the annobin setup.

There was already a hint in b2ea64fd
that we lack some packaging stability from the platforms we support
and this is another occurrence. The configure script of a supported
Varnish release will find the tools we need.

This enables build support for el8 in addition to el7.

We don't care when a pipeline does not read the complete varnishadm
output because it found what it needed way before. However, we don't
want noise in the standard error with spurious broken pipe messages.

Closes #134

Slightly better diff with the --ignore-all-space option.

Refs #134

Refs #104

I was finally able to use sbuild on Fedora for all Varnish 6 Debian and
derivatives. I was able to confirm that the configure script doesn't
need help to find our documentation tools. Or rather, I was no longer
running in that error when I rushed the Python 3 transition.

https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2019-5f2841e1a2

And incidentally rst2html became mandatory in trunk. Because of another
python3 packaging "bug" on epel7 we don't have a stable virtual provides
for docutils, but we can get it via the stable:

    BuildRequires: python3-sphinx

The problem with dependency "stability" was our reliance on python3.4
packages, recently replaced by python3.6 packages when 3.4 reached its
EOL. With this change we should no longer have a problem when python
3.6 goes EOL too.

I needed to pass `--enablerepo testing` to check a python3-docutil
packaging fix.

Python 2 support is over in 3 quarters, and python 2 support is over in
2 days in Varnish.