Libtool-2.4

[Matthew Burgess]

New version. From NEWS:

  - Sysroot support.  This allows you to build cross-compiled packages
    with the same prefix that will be used on the destination machine,
    and still find dependent libraries under the compiler's "sysroot".
    Without sysroot support, paths internal to the build system may leak
    into the product of the build.

    Sysroot support is disabled unless the --with-sysroot configure
    option is passed to configure, because .la files generated with
    sysroot support will _not_ be usable in general with older Libtools.

  - On non-cygwin Windows systems, we now lookup potential library
    file names without regard to file name case.
  - The old testsuite now uses the `parallel-tests' Automake test driver
    now for more concurrency and better test logging.  For this, tests are
    run in verbose mode by default now.

[Matthew Burgess]

Fixed in r9396.