ChangeLog, ext2_err.et.in, ext2fs.h, initialize.c, mkjournal.c, openfs.c:

ChangeLog, ext2_err.et.in, ext2fs.h, initialize.c, mkjournal.c, openfs.c:
  initialize.c (ext2fs_initialize): Add support for initializing the
  	ext2 superblock for external journal devices.  This basically means we
  	don't bother to allocate any block group descriptors.
  openfs.c (ext2fs_open): Only open external journal devices if the new
  	flag EXT2_FLAG_JOURNAL_DEV_OK is passed to ext2fs_open.  When opening
  	such devices, don't try to read the block group descriptors, since
  	they're not there.
  ext2_err.et.in (EXT2_NO_JOURNAL_SB): Add new error code
  mkjournal.c: Export a new function,
  	ext2fs_create_journal_superblock(), which allocates and returns a
  	buffer containing a journal superblock.  This is needed by mke2fs to
  	create an external journal.  Rewrote ext2fs_add_journal_device() so
  	that it no longer creates the external journal, but rather adds a
  	filesystem to an existing external journal.  It handles all of the
  	UUID manipulation.
  ext2fs.h: List the EXT3_FEATURE_JOURNAL_DEV as a flag supported by the
  	library.  Define the EXT2_FLAG_JOURNAL_DEV_OK.  Changed function
  	prototype for ext2fs_add_journal_device().