Mega-patch for 2.2.Stable3 + fastest redirector in town

This patch is relative to squid-2.2.Stable3.
It is an almost complete snapshot of my production server.

What it does:
- Uses a partially memory mapped store metadata.
- Because of this, it allows instant restarts after
  a crash or termination of squid.
- It allows immediate proxying operation without
  having problems with stale URLs pointing to the
  wrong (newer) swapfile.
- Instant termination without needing to write out
  the swaplog metadata.
- Memory pools that never shrink.
- Memory pools that reuse other pools with the same
  object size.
- Vastly reduced overall memory footprint.
- Integrates the recent HPL_REPL heap replacement
  strategies (a few bugs fixed and optimised relative
  to the posted version).
- More aggressive and fair loadbalancing across several
  spindles (especially important when adding an empty
  drive to several other full drives).
- Perform swap-in consistency checks to avoid
  handing out the wrong cached file in *any* case
  (not that it catches anything currently, but it
  helps prevent disasters while hacking :-).
- Support for the cuciwhirl redirector (i.e. terminate
  redirect URLs with double newlines to improve speed).
- Some minor bugfixes here and there.

The sources should compile as is, the tiny.gif file
is just an empty 1x1 transparent gif, but could
be made anything else.

Due to time constraints I have not had the time to
backcheck what happens if the MMAPSTORE, NEVERFREE
and HPL_REPL macros are turned off. I tried to make
things backward compatible, but didn't explicitly
verify its sanity. So if you encounter problems compiling
the source with those macros turned off, don't be surprised.

If someone has time to sanitise the patch to get it into
mainstream squid, be my guest.

The patch can be found as:

ftp://ftp.cuci.nl/pub/squid/dif.2.2.S3-BuGless.gz

The fastest redirector ever built can be found as:

ftp://ftp.cuci.nl/pub/squid/cuciwhirl-1.5.tar.gz

Squid times it at 0 ms consistently on my production machines,
and you actually only need *one* redirector, although, for good
measure I usually use 2; but the second one doesn't get much
use.

Sources delivered as is, with a 30-day money back
guarantee.

-- 
Sincerely,                                                          srb@cuci.nl
           Stephen R. van den Berg (AKA BuGless).
"<Clarions sounding> *No one* expects the Spanish inquisition!"