narrow race while we're at it.

ESI include is off the waiting list.

Many thanks to Nils for pushing for us to fix this.

Superceedes #1902

under the oh->mtx.  2 rush them out of the mtx.

As discussed with phk: Callers of Lck_CondWait with timeout should
be prepared for early wakeups.

trying to snipe.  If they did, fail the sniping.

Fixes #1942

Reduces my stash list to 62 entries.

This has been superseded by return (miss).

Use builddir and other minor cleanups while here.

miniobj magics.

a family of tickets related to it (#1933 #1920 #1898 (?) #1888 and #1865 (?))

with a resounding yes!

The ban lurker checks bans concurrently to lookup. Lookup checks are better
informed then ban lurker checks, in particular because they have access
to request information and can thus check request bans.

So, do not touch ocs which were moved concurrent to the ban lurker working them.

Unprotected access to oc->ban may be outdated, so re-check under the ban_mtx.

Idea for great simplification by
Martin Blix Grydeland <martin@varnish-software.com>

All bans on olist can get marked completed as duplicates while we're
working on them, in particular as we start at an offset of
ban_lurker_age.

Fixes #1919

Fixes #1928

Updated formatter %{VSL:tag}x to mirror the VQL. The documentation has
been updated accordingly.

The formatters %{Varnish:vxid}x and %{VSL:key[:field]} are introduced,
with documentation. Also updated copyright in the varnishncsa.c file.

A new mode, backend mode, in varnishncsa is introduced. It lets you
log trafic from varnish to the backends. The normal (default) mode is
now named "client mode" and can be explicitly selected using -c. You
can run varnishncsa in backend mode in addition to varnishncsa in
client mode, but it is also possible to run in mixed mode by
specifying both -b and -c.

New formatter added: %{Varnish:side}x will be either "b" or "c",
depending on where the request was made.

This log record is a counterpart to the SLT_ReqStart for backends, and
shows the socket endpoint we are talking to at the start of backend
requests. Today this information is only logged on opening a backend
connection (SLT_BackendOpen), and is thus not available on the backend
log transaction when on a reused backend connection.

We need this information to complete the backend view varnishncsa
extension.

When the VEP state machine is in a bad state during finalization
(VEP_Finish), we log this as an ESI error.

When an ESI tag contains an unterminated quote or misses its ending
'>', we release the relevant buffers instead of crashing.

Fixes: #1904

Fixes #1917

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