and variable names filtering.

    Make the format of Environment Block plain text. The boot loader
    part is not tested well yet.
    
    * util/grub-editenv.c (DEFAULT_ENVBLK_SIZE): New macro.
    (buffer): Removed.
    (envblk): Likewise.
    (usage): Remove "info" and "clear". Add "unset". Update the
    description of "set", as this does not delete variables any
    longer.
    (create_envblk_file): Complete rewrite.
    (open_envblk_file): Likewise.
    (cmd_info): Removed.
    (cmd_list): Likewise.
    (cmd_set): Likewise.
    (cmd_clear): Likewise.
    (list_variables): New function.
    (write_envblk): Likewise.
    (set_variables): Likewise.
    (unset_variables): Likewise.
    (main): Complete rewrite.

    * commands/loadenv.c (buffer): Removed.
    (envblk): Likewise.
    (open_envblk_file): New function.
    (read_envblk_file): Complete rewrite.
    (grub_cmd_load_env): Likewise.
    (grub_cmd_list_env): Likewise.
    (struct blocklist): New struct.
    (free_blocklists): New function.
    (check_blocklists): Likewise.
    (write_blocklists): Likewise.
    (grub_cmd_save_env): Complete rewrite.

    * include/grub/lib/envblk.h (GRUB_ENVBLK_SIGNATURE): Replaced with
    a plain text signature.
    (GRUB_ENVBLK_MAXLEN): Removed.
    (struct grub_envblk): Complete rewrite.
    (grub_envblk_find): Removed.
    (grub_envblk_insert): Likewise.
    (grub_envblk_open): New prototype.
    (grub_envblk_set): Likewise.
    (grub_envblk_delete): Put const to VALUE.
    (grub_envblk_iterate): Put const to NAME and VALUE.
    (grub_envblk_close): New prototype.
    (grub_envblk_buffer): New inline function.
    (grub_envblk_size): Likewise.

    * lib/envblk.c: Include grub/mm.h.
    (grub_env_find): Removed.
    (grub_envblk_open): New function.
    (grub_envblk_close): Likewise.
    (escaped_value_len): Likewise.
    (find_next_line): Likewise.
    (grub_envblk_insert): Removed.
    (grub_envblk_set): New function.
    (grub_envblk_delete): Complete rewrite.
    (grub_envblk_iterate): Likewise.

	* commands/crc.c: New file.

	* lib/crc.c: Likewise.

	* include/grub/lib/crc.h: Likewise.

	* util/grub-fstest.c: grub/hexdump.h => grub/lib/hexdump.h.

	* commands/hexdump.c: grub/hexdump.h => grub/lib/hexdump.h.
	(hexdump): Move this function to ...

	* lib/hexdump.c: ... here.

	* include/grub/hexdump.h: Renamed to ...

	* include/grub/lib/hexdump.h: ... this.

	* commands/loadenv.c: grub/envblk.h => grub/lib/envblk.h

	* util/grub-editenv.c: Likewise.

	* include/envblk.h: Renamed to ...

	* include/lib/envblk.h: ... this.

	* util/envblk.c: Renamed to ...

	* lib/envblk.c: ... this.

	* conf/common.rmk (grub_fstest_SOURCES): commands/hexdump.c =>
	lib/hexdump.c.
	(grub_editenv_SOURCES): util/envblk.c => lib/envblk.c
	(pkglib_MODULES): Add crc.mod.
	(hexdump_mod_SOURCES): Add lib/hexdump.c.
	(loadenv_mod_SOURCES): util/envblk.c => lib/envblk.c.
	(crc_mod_SOURCES): New macro.
	(crc_mod_CFLAGS): Likewise.
	(crc_mod_LDFLAGS): Likewise.

	* conf/i386-coreboot.rmk (grub_emu_SOURCES): Add lib/hexdump.c.

	* conf/i386-efi.rmk (grub_emu_SOURCES): Likewise.

	* conf/i386-pc.rmk (grub_emu_SOURCES): Likewise.

	* conf/powerpc-ieee1275.rmk (grub_emu_SOURCES): Likewise.

	* conf/x86_64-efi.rmk (grub_emu_SOURCES): Likewise.

	* conf/common.rmk (bin_UTILITIES): Add grub-editenv.
	(grub_editenv_SOURCES): New variable.
	(pkglib_MODULES): Add loadenv.mod.
	(loadenv_mod_SOURCES): New variable.
	(loadenv_mod_CFLAGS): Likewise.
	(loadenv_mod_LDFLAGS): Likewise.

	* include/grub/envblk.h: New file.

	* util/envblk.c: New file.

	* util/grub-editenv.c: New file.

	* commands/loadenv.c: New file.