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

diff -ur uClibc-0.9.29/libc/inet/resolv.c uClibc-0.9.29-patched/libc/inet/resolv.c

--- uClibc-0.9.29/libc/inet/resolv.c	2007-04-23 12:01:05.000000000 -0500

+++ uClibc-0.9.29-patched/libc/inet/resolv.c	2007-05-09 18:05:33.563404419 -0500

@@ -1700,7 +1700,7 @@

 int gethostent_r(struct hostent *result_buf, char *buf, size_t buflen,

 	struct hostent **result, int *h_errnop)

 {

-    int ret;

+    int ret = HOST_NOT_FOUND;

     __UCLIBC_MUTEX_LOCK(mylock);

     if (__gethostent_fp == NULL) {