Just "packed" doesn't always pack the way we expect.

	for all archives to a separate module. This splits tar from cpio
	as they are very different but keeps cpio, cpio_be, odc and newc
	together since they're very similar.

	rename remaining to cpio_common.c

	* Makefile.util.def (libgrubmods): Add odc.c, newc.c and cpio_be.c.
	* grub-core/Makefile.core.def (newc): New module.
	(odc): Likewise.
	(cpio_be): Likewise.
	* grub-core/fs/cpio.c (ALIGN_CPIO): New macro.
	(MAGIC): Likewise.
	(MAGIC2): Likewise.
	(head) [MODE_ODC]: Adapt for the format.
	(head) [MODE_NEWC]: Likewise.
	(head) [!MODE_*]: Write fields of interest as arrays.
	(MAGIC_USTAR): Removed.
	(read_number) [MODE_NEWC]: Change to hex.
	(read_number) [!MODE_*]: Parse binary arrays.
	(grub_cpio_find_file): Factor out the code for better structure and
	always use read_number.
	(grub_cpio_mount): Use MAGIC and MAGIC2.
	(grub_cpio_dir): Exit on first hook non-0 return.
	(grub_cpio_fs) [MODE_ODC]: Set name to odc.
	(grub_cpio_fs) [MODE_NEWC]: Set name to newc.
	(GRUB_MOD_INIT) [MODE_ODC]: Set name to odc.
	(GRUB_MOD_INIT) [MODE_NEWC]: Set name to newc.
	(GRUB_MOD_FINI) [MODE_ODC]: Set name to odc.
	(GRUB_MOD_FINI) [MODE_NEWC]: Set name to newc.
	* grub-core/fs/newc.c: New file.
	* grub-core/fs/odc.c: Likewise.
	* grub-core/fs/cpio_be.c: Likewise.