The counter g_cooling variable is now decremented when memory from the
cooling list is freed, making the counter vsm_cooling update
accordingly.

Fixes: #1984

This new parameter specifies how long freed VSM memory is on the
cooling list before it is actually freed.

If an object marked OF_IMSCAND is used as the template during backend
IMS revalidation, and the new object also is marked OC_F_PASS
(hit-for-pass) in vcl_backend_response, the resulting object would
(though ObjCopyAttr) have both OF_IMSCAND and OC_F_PASS. The object
could then be used again for backend IMS revalidation (since it has
the OF_IMSCAND flag), which would cause troubles as the body would by
this time be deleted.

Fix by not considering objects marked OC_F_PASS as a stale object
candidate during lookup.

Fixes: #1956

An object failing fetch that is waited upon by the ESI delivery code
would cause asserts finding an empty object. If waiting for an object,
check the status of the object and deliver zero bytes if failed.

Fixes: #1953

Conflicts:
	include/vsb.h
	lib/libvarnish/vsb.c

miniobj magics.

Conflicts:
	bin/varnishd/cache/cache_panic.c

An object is delivered to the client, not to the backend.

Conflicts:
	autogen.des

function.

Maybe we should have a configure-time test to see if it actually works,
but for now, just make autogen.des handle it.

Conflicts:
	autogen.des

Rename will fail across different mount points.

Last minute changes...

By writing output byte by byte, the calling parallel make would start
jobs depending on the completed files too soon.

Avoid this by writing to temporary files and move the completed results
into place.

Fixes: #1921

Output a proper error message instead of a more cryptic assert
if the vmod writer does the wrong thing.

Ref: #1811

Pointed out by Jean-François Laurens.

Conflicts:
	bin/varnishd/cache/cache_fetch.c

whitespace) testfiles.

Spotted by:	Coverity

In particular, this avoids a later backend.list attempt on a file descriptor
to a dead process and, consequently, avoids a long delay in varnishtest
when varnishd cant be started (for instance, because it is not in PATH).

Ref: #1924

Related to #1924.