libltdl -- planning to change configure.in and friends.

[Rob Browning]

Unless people object, I'm going to change all our versions of guile to
use the system libltdl when it's available.  Not doing this seems to
be in conflict with guile's aspirations on the extension language
front, and it prevents guile from benefiting from inter-guile-version
libltdl bugfixes.

For example, Stefan and I have just tracked down two nasty bugs in
libltdl that will cause it to segfault under various conditions.  Even
if debian, for example, were to release a new libltdl package with the
fixes, guile would have to be re-built from scratch (or someone has to
use LD_PRELOAD tricks) to take advantage of them.

I believe the fix is probably just a one line change to configure.in.
At least that's what the libtool docs say, and it seems to work here.

-- 
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
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