utime: remove obsolete module This module, like autoconf's AC_FUNC_UTIME_NULL macro, has been unnecessary for years, and has been marked as obsolete for 10 months. * modules/utime: Remove file. * lib/utime.c: Remove file. * m4/utime.m4: Remove file. * m4/utimes-null.m4: Remove file. * doc/posix-functions/utime.texi (utime): Remove reference to the module. Move the sole "fixed by gnulib" item into the "problems not fixed by Gnulib" list. * MODULES.html.sh (func_all_modules): Remove reference to "utime".