Modern versions of gcc and clang support various runtime sanitizers that
can be used to find nasty bugs at runtime. Note that not all of these
sanitizers may be active at the same time. However, these tools are aimed
at developers and likely require at least some level of reference during
testing while enabled -- which discouraged me from doing a matrix of
conditionals in autohell.

We'll need to change a couple of signatures in the call paths getting here
to propagate up the failure.

This fix avoids a WS_Alloc panic when pushing fetch processors
and should thus avoid panics by overflowing the backend workspace in vcl.

This overflow is logged as FetchError "Bo workspace overflowed".

Other panic points due to workspace_backend being set too low still exist.

Sizing estimate for workspace_backend:

	sizeof(struct busyobj)
	+ 3 * HTTP_estimate(cache_param->http_max_hdr)
	+ cache_param->vsl_buffer
	+ cache_param->http_resp_size
	+ fetch processor memory
	+ space required in VCL

Fixes #1739

As discussed on irc.  OK'd by phk@.

OK'd by phk@.

Allow to split https URI in the request line

it contribute panic dumping methods

Just warn unless --strict is used.  This allows to use the same .vcc in
4.0 and 4.1.

session number.

When building multiple vmods from the same source directory,
vmodtool would trample on other concurrent jobs' vcc_if.[ch].

Pointed out by phk@.

Using os.path.join() instead of string concatination is easier
to read.

I've verified the rest and only these 2 were affected.

Always use an oc+TRANSIENT for buffering, just don't commit the
storage if not caching.

tour through vcl_recv{}

Fixes: #1857