I hadn't realized how unsuitable vtc_varnish was to copy from,
because of the dual process complications, this simplifiles
things back again.

Move -D and -W out of -arg, it makes no sense to have to pull
them out of there again.

Add -conf-OK and -conf-BAD arguments.

handling.

Add -conf+backend to automatically produce backend confs
from list of servers

Enforced for HTTP/1.1 requests. To disable it use -nohost.

Prep work for upcoming change.

do want VTEST to do so.

It is only during cleanup, so this *may* be an adequate bandaid.

Also a trivial coverage tes which runs if haproxy is in $PATH.

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

Addresses #2626.

Move misc commands to separate source file.

the directory where the .vtc file lives.

Suggested by:	HAproxy

Without it, graphing Timestamp tags was impossible for all practical purposes

Related to #2626.

We already check the -a user input and emit an error if the path is
too long.

bprintf() should help persuade static analysis tools that we won't
overflow the fixed-size buffer.