Fixes:	#2745

Conflicts:
	bin/varnishtest/tests/v00020.vtc

... argument to specify a custom location

Fixes #2742

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

The output changes in Varnish 6.1 and that check slipped through the
cracks.

Fixes: #2603

in order to have it build first and cleaned up

fixes this issue when switching to an older branch:

$ git checkout ...
error: The following untracked working tree files would be overwritten
by checkout:
	bin/varnishtest/vtc_h2_dectbl.h
Please move or remove them before you switch branches.
Aborting

This still lacks error handling and thus is not a fix for #2589, but at
least we're not writing past the end of the workspace any more.

header lines.

Fixes:	#2678

Fixes: #2682

after the headers.

Fixes: #2731

Start pylinting while here anyway.

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

Closes: #2737

Fixes: #2729

counting deck-chairs on the Titanic.

client content -> client context

this tests d912ffe4

Tweaked:
	bin/varnishtest/tests/d00007.vtc

In 6.0 this bug doesn't exist and directors behave slightly differently
so the test case needed some adjustments to both show that a backend can
be added to an already warm VCL with a probe, and that requests succeed.

This was a proof of concept for an alternative WS interface -- write
incrementally to reserved workspace as an "open buffer".

That may be generally useful for Varnish, but for now we return to
the usual WS_* idiom.

The error may be status 500 on 32-bit systems.

On the various platforms, esp 32-bit, workspace may be exhausted
before it gets to the VMOD at all, so we can't reliably expect
specific error messages.

This has nevertheless improved GCOV coverage, which was the goal.

To get some better GCOV coverage. So far just IDENTITY encoding.

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

Closes #2722