#1 New config.m4

[Sean Bolt]

Extended the config.m4 to accept a swich
--with-libxml2-dir=DIR to specify the loction vs
hardcoding to /usr/local. If the --with-libxml2-dir
switch isn't used the m4 is set to try and find it.

Once located it will then check the library version to
make sure it meets a minimum requirement (2.4.2 at the
moment since this matches the requirement of the domxml
module).

Also checks to ensure zlib is enabled as well.

Still need to check it under a few different build
conditions.

FWIW, I'm on Mandrake 8.2 using php 4.2.1 srpms from
the cooker.

[Sean Bolt]

config.m4