* grub-core/Makefile.core.def (kernel): Add kern/emu/argp_common.c on
	emu.
	* util/argp_common.c: Rename to ...
	* grub-core/kern/emu/argp_common.c: ... this. All users updated.
	Add missing includes.
	* grub-core/kern/emu/main.c: Convert to argp.
	* po/POTFILES.in: Regenerate.
	* util/grub-install.in (usage): Make first letter lowcase in messages
	for uniformity.
	* util/grub-setup.c (options): Likewise.