setup changes to build standalone

["Robert Collins" <robert dot collins at itdomain dot com dot au>]

To build setup we need:
a mingw bz2lib
a mingw zlib
w32api
in the future (soon I hope):
a mingw libstdc++ (and any dependencies it has).

So,
I've made a copy of bz2lib from src/winsup/bz2lib to set/bz2lib, and
adjusted accordingly.

A second issue is that I cannot get configure to play nice in the new
location without updating to 2.5x. That doesn't concern me, does it
concern anyone else?

The configure line to prepare a website version of setup will be:
../setup/configure' --host=i686-pc-mingw32 --build=i686-pc-cygwin
'CC=gcc -mno-cygwin' 'CXX=g++ -mno-cygwin'.

It should configure and build a cygwin1.dll linked version quite happily
if the --host parameter is left off. That may also be useful for test
builds and the like, and also for building command line mirroring tools
etc etc.

I'll post a patch (probably up on sources.redhat.com/cygwin-apps/setup)
when I've got everything ready. (It's gonna be big (at least the size of
bz2lib :}) or I'd just drop it here). Then if a couple of folk have
success with it, I'll check it in.

Any comments, peanuts, etc?

On a separate but related topic, I'd like to automakeise (is that a
word) setup - if there are no objections from the other contributors.
I'll do this as a separate commit, that is if noone has serious issues
with it.

Rob