autoconf conversion

[Andrew Tridgell]

The HEAD branch in CVS (ie. the 1.9.19 development tree) will be
converted to autoconf later this week, probably on Thursday.

For those of you who don't know, we have been waiting a long time to
convert Samba to use autoconf and the time has finally come. I've done
most of the work over the last few days and expect to get it to a
usable state soon. Those of you on the samba-cvs list will have seen
huge numbers of commits to a branch called "autoconf2".

When I merge into the main branch I will be locking down the tree for
a few hours, then merging. The lockdown is needed because this will be
a large change to a very large number of files. After I've done the
merge everyone with a checked out copy of the tree will find that a
update will pull in a large pile of changes, which may well conflict
with any local changes you have in your sandbox.

The autoconf merge will break some things on some platforms, so after
the merge we will need as many people as possible to test whatever
platforms they have available and send me bug reports. 

The autoconf merge should be a big win for portability and
performance. Many platforms currently use incorrect or sub-optimal
code because the person who did the port didn't correctly set all the
USE_XXX and HAVE_XXX bits in includes.h. After the merge all those OS
specific sections in includes.h will be gone and replaced instead by a
pile of compile time tests that check for the features explicitly.

Right now the autoconf stuff is working to the point where it compiles
and runs on several platforms, although it doesn't yet test properly
for some important OS features. I'm testing on:

Linux 2.1 (RH 5.0)
IRIX 6.4
AIX 4.2
Solaris 2.6

Before I do the final merge I'll also do some compile-only tests on:

SunOS 4.1.3
Ultrix 
Digital Unix

I don't recommend trying the autoconf2 branch right now (unless you
_really_ want to) as it is changing rapidly, and may be broken at any
one moment.

	Cheers, Tridge