remove strerror module

remove strerror module

This fixes the mingw build breakage reported by Pierre.

I found that the gnulib strerror module somehow requires us to pull in
the gethostname module.  However, pulling in the gethostname module
makes many things break.

I've sent a bug report to gnulib.

Meanwhile, removing the strerror module should not harm gdb and fixes
the build.

I'm checking this in.

2013-11-20  Tom Tromey  <tromey@redhat.com>

	* gnulib/update-gnulib.sh (IMPORTED_GNULIB_MODULES): Remove
	strerror module.
	* gnulib/aclocal.m4: Update.
	* gnulib/config.in: Update.
	* gnulib/configure: Update.
	* gnulib/import/Makefile.am: Update.
	* gnulib/import/Makefile.in: Update.
	* gnulib/import/errno.in.h: Remove.
	* gnulib/import/intprops.h: Remove.
	* gnulib/import/m4/errno_h.m4: Remove.
	* gnulib/import/m4/gnulib-cache.m4: Update.
	* gnulib/import/m4/gnulib-comp.m4: Update.
	* gnulib/import/m4/strerror.m4: Remove.
	* gnulib/import/m4/sys_socket_h.m4: Remove.
	* gnulib/import/strerror-override.c: Remove.
	* gnulib/import/strerror-override.h: Remove.
	* gnulib/import/strerror.c: Remove.
	* gnulib/update-gnulib.sh: Update.