A VCL label is a symbolic name pointing to a "real" VCL program.

VCL labels can be the active VCL and can be repointed to a different
VCL at any time.

Labels are always warm, and can be discarded with vcl.discard if not
in use.

Labeled VCLs are _also_ always warm.

One possible use could be for site develpment to label a "production",
and a "emergency" VCL so operations personel only have to know
these two labels, not worrying about versioning of the VCLs.

Of course I have other interesting evil plans for this too...

a couple of unnecessary includes of it.

and the VCLI core serve code.

resulting in alphabetically sorted command listing.

Not what I set out to do right now, but somebody asked for this
recently and I happened to spot a way to do it now...

whitespace) testfiles.

Spotted by:	Coverity

This makes it possible to add a "varnishd -x dumprstcli" command.

Handle symbols are ACL, BACKEND, PROBE and STEVEDORE, they are not
variables, but "things which do stuff".

The only real difference from variables (like resp.status) is that
when they are stringified (resp.http.foo = BLA) they return the
name of the thing (ie: backend, acl ... name) rather than a value,
which they don't have.

Handles are by definition available everywhere.

Global symbols are handles available in any VCL (ie: STEVEDOREs).

This means that if you:

	acl foobar { .... }

	sub vcl_recv {
		set req.http.acl = foobar;
	}

Then the HTTP header gets set to the name of the ACL, ie: "foobar"

people to throw return values away if the want to, but not to
use VOID in expressions.

Submitted by:	rezan
Fixes:		#1931

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).

Related to #1924.

Fixes #1924.

ban_lurker_work completes bans by moving ocs up the ban list. Unless
there are REQ bans, this leaves a tail of completed bans which,
previously, got marked by ban_mark_completed() only to get removed by
ban_clean_tail() in the next step

We now clean out the completed tail in the first place, avoiding the
extra marking step.

Fixes https://github.com/nigoroll/varnish-modules/issues/1