Fixes #1917

Lack of this interface breaks existing vmods, so should we really need to
remove it, we problable should provide an alternative.

We may not have permission to unlink vp.dir

$ /etc/init.d/varnish_master restart
Stopping Varnish Cache:                                    [FAILED]
Starting Varnish Cache: Assert error in mgt_VccCompile(), mgt/mgt_vcc.c line 302:
  Condition((rmdir(vp.dir)) == 0) not true.
  errno = 13 (Permission denied)

wait for it to arrive.

Fixes #1912

The fact that the oc expired does not mean that the OC is going away
any time soon: It may be delivering War&Peace to a mobile phone in
outher Elbonia for quite some time still.

private.

Rename EXP_Poke() to EXP_Remove()

This made gmake mandatory which is not ideal.  The code will be
fixed outside the tree and added back once it's free from any GNUism.
Discussed with dridi@.

Older libedit versions lack rl_set_prompt() and in some cases we ended
up with an empty prompt.

Tested by scn.  Fixes #1899.

I don't think we can assume that everyone knows that PSK is, and
with the extensive acronym soup in use in Varnish it is hard
for the user to know if we have overloaded it.

Use 0 to indicate it has not been set instead of displaying abandon.

Instead of panicking on a return(synth()) in vcl_pipe, we just proceed
to a normal synth.

Test by Dridi

Fixes #1890

eat all CPU time.

in both client and backend context.

Connections to backends so configured are never reused.

at client/server IPs.

what sockaddr-hack it is destined for.