* .gnulib: Update, for sc_prohibit_strcmp fix.
* cfg.mk: Adjust copyright; the only FSF portions come from when
this file was copied from coreutils.
(sc_prohibit_strncmp): Copy bug-fixes from sc_prohibit_strcmp.
* .x-sc_prohibit_strcmp: Delete, now that rule is smarter.
* .x-sc_prohibit_strncmp: Likewise.
* Makefile.am (syntax_check_exceptions): Track deletion.