path for fonts ($prefix/fonts).
	* grub-core/kern/corecmd.c (grub_core_cmd_insmod): Unify condition
	for checking if string is a path.
	* grub-core/normal/main.c (features): Add feature_default_font_path.
	* util/grub-mkconfig.in: Skip mangling of GRUB_FONT into GRUB_FONT_PATH.
	* util/grub.d/00_header.in: Use default directory if possible.
	* util/grub-install.in: Install unicode.pf2.