configure.ac: respect 'g' variants of libtool/libtoolize

BSD OS'es (OS X for me) provide GNU tools with prefixed 'g'. To find correct
versions of libtool/libtoolize on those systems search also for
glibtool/glibtoolize.

Signed-off-by: Andreas Bießmann <andreas@biessmann.de>
Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
[yann.morin.1998@free.fr: search for the g-variant first]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <2f1530b54afcb6a00e1d.1395158786@andreas-mbp.er.biessmann.org>
Patchwork-Id: 331467

# This file declares functions to install the kernel headers for mingw64

# Copyright 2012 Yann Diorcet

# Licensed under the GPL v2. See COPYING in the root of this package

CT_DoKernelTupleValues() {

    # Even we compile for x86_64 target architecture, the target OS have to

    # bet mingw32 (require by gcc and mingw-w64)

    CT_TARGET_KERNEL="mingw32"

    CT_TARGET_SYS=

}

do_kernel_get() {

    :

}

do_kernel_extract() {

    :

}

do_kernel_headers() {

   :

}