FYI: cygwin dlopening backends

[Ralf Wildenhues]

Applied this to HEAD.  Fixing the rest of this mess (including Charles'
other observed ltdl bug) is independent and will follow in another
patch.

Cheers,
Ralf

* Ralf Wildenhues wrote on Sun, Nov 13, 2005 at 11:11:56PM CET:
> 
> 2005-11-13  Eric Blake  <address@hidden>,
>             Ralf Wildenhues  <address@hidden>
> 
>         * libltdl/ltdl.h, libltdl/ltdl.c (lt_dlinterface_free): New
>         function.
>         * doc/libtool.texi (User defined module data): Document it.
> 
>         * libltdl/loaders/loadlibrary.c (iface_id): New variable.
>         (get_vtable): Get an `iface_id' from `lt_dlinterface_register'.
>         (get_vtable): Rewrite to catch up with lt_dlhandle_iterate
>         interface change.  Append dot only after w32 path conversion
>         so it works on cygwin managed mounts.