> I think we should link and use the LDAP library just like we link and
use all the other external libs we use.

Here is the patch !

This was not that easy, since there are a lot of different cases:
openldap/winldap, linux/win$ and the hybrids like cygwin.
By the way, the dlfcn version was not working on hybrids (because
ldap_url_parse() is undefined!). Should be working with this patch.

The patch defines its own LDAP prototypes for all but win$ and hybrids,
because there are too many different versions of /usr/include/ldap.h,
and because we already have a file called ldap.h :-(

I tried to remove everything about dlfcn from the code and the various
config and build files. I hope I did not removed too much.

I tested this patch successfully on Linux (FC6) and on cygwin: these are
the only "standard" platforms I have access to. I think some additional
compilation tests on other platforms should be done before committing,
for example with MSC.

Please let me know about your successes or failures, or when OK to
commit.