* merged my inter-library dependencies code from the ILD branch:

* merged my inter-library dependencies code from the ILD branch:
* NEWS: inter-library dependencies are now supported
* configure.in: add the depdemo subdirectory
* depdemo/*: new demo to demonstrate inter-library dependencies
* tests/depdemo*: new tests for depdemo
* ltconfig.in: added hardcode_into_libs (whether library paths
  should be hardcoded into the libraries),
  it currently defaults to 'no'
* ltmain.in: new internal 'relink' mode to relink libraries
  on platforms with hardcode_into_libs=yes, save command line
  arguments in libtool_args, accept relative -L directories,
  ignore -lm on BeOS and Cygwin, always ignore -lc,
  handle -l, -L and .la arguments later, always make the library
  installation directory (-rpath) absolute, in relink mode don't
  delete the not-relinked library and exit immediately after relinking,
  try to find already-installed libtool libraries that were specified
  using -l, support hardcoding of library paths into libraries too,
  export shlibpath before linking libraries, and a lot of other
  big changes that I don't want to describe here... please read
  the source.

* merged Gary's Win32 code from the ILD branch:
* NEWS: Win32 DLLs are now supported
* TODO: removed .a library namespace clash for win32.  It is
  now resolved.
* ltconfig.in (cygwin, library_names_spec):  removed $libname.a.
  Creating a dll with libtool no longer creates an import library.
* ltconfig.in (extract_expsyms_cmds): Create $objdir if it does
  not exist -- i.e. we need to generate import an import library
  in a directory which has no libs of its own.
* doc/libtool.texi (old_archive_from_expsyms_cmds,
  extract_expsyms_cmds): documented these new variables.
* ltconfig.in (extract_expsyms_cmds): New variable.  Commands to
  extract the exported symbol list from a dll.
  (old_archive_from_expsyms_cmds): New variable.  Commands to build
  an old archive from the extracted expsyms list.
* ltmain.in: run the cmds in extract_expsyms_cmds and
  old_archive_from_expsyms_cmds as necessary.
* ltconfig.in (cygwin, old_archive_from_new_cmds): no longer
  required.
* ltconfig.in (cygwin, shlibpath_overrides_runpath): I'm not even
  sure whether win32 honours the runpath at all when searching for
  a dll to load!  Anyway, when set to yes this prevents a gratuitous
  warning.
* ltmain.in (deplib): The cygwin environment doesn't actually have
  -lm, and although the linker fakes having one, specifiying it to
  libtool will break ILD, so we ignore it when generating
  dependencies.