Author: Frédéric Lécaille <flecaille@haproxy.com>
    Date:   Mon Jul 15 15:20:07 2019 +0200

    Open and close a TCP socket to simulate an unreachable server.

    This is done for each haproxy instance. The socket address (resp. port)
    may be referenced by ${<name>_closed_addr} (resp. ${<name>_closed_port})
    variable where <name> is the haproxy instance name.

Also collect in one single place that HASH is the default.

Also update svg and dot files.

Reported on irc by idl0r.

While here also implement -gziplen and -gzipbody.

Fixes #3031.

Fixes #3030.

The behavior described here is old (see cache_fetch.c), but has
not been cleanly documented in the docs.

Fixes: #3024

When executing vcl.show for labels, show the VCL the label points to
instead of asserting.

segments dominate the _.index file.

Relevant for #3023

Be a bit more elaborate on the expected behaviour