ZFS crypto support.

	ZFS crypto support.

	* Makefile.util.def (libgrubmods): Add grub-core/fs/zfs/zfscrypt.c.
	* grub-core/Makefile.core.def (zfscrypt): New module.
	* grub-core/fs/zfs/zfs.c (subvolume): New structure.
	(grub_zfs_data): Replace mdn with subvol. Put case_insensitivity inside
	it. All users updated.
	(grub_zfs_decrypt): New var.
	(grub_zfs_load_key): Likewise.
	(zio_checksum_functions): Add SHA256+MAC.
	(zio_checksum_verify): Handle incomplete comparison due to MAC.
	(zio_read): Handle encrypted blocks.
	(zap_verify): Remove incorrect check.
	(fzap_iterate): Handle non-standard fzap.
	(zap_iterate): Likewise.
	(zap_iterate_u64): New function.
	(dnode_get_fullpath): Load keys.
	* grub-core/fs/zfs/zfscrypt.c: New file.
	* grub-core/lib/crypto.c (grub_crypto_cipher_close): Removed.
	(grub_crypto_ecb_encrypt): Make input const.
	* include/grub/crypto.h (grub_crypto_cipher_close): Inline.
	(grub_crypto_ecb_encrypt): Make input const.
	(GRUB_CIPHER_AES): New macro.
	* include/grub/zfs/dmu.h (dmu_object_type): Add DMU_OT_DSL_KEYCHAIN.
	* include/grub/zfs/dsl_dir.h (dsl_dir_phys): Add keychain.
	* include/grub/zfs/spa.h (grub_zfs_endian): Moved from here ...
	* include/grub/zfs/zfs.h (grub_zfs_endian): ... here. Added GURB_ZFS_
	prefix. All users updated.
	(grub_zfs_add_key): New proto.
	(grub_zfs_decrypt): Likewise.
	(grub_zfs_load_key): Likewise.
	* include/grub/zfs/zio.h (zio_checksum): Add SHA256+MAC.
	* util/grub-fstest.c (options): Add -K option.
	(argp_parser): Likewise.