* dump.c (dump_db): Update usage comment. Add "-rev" and

	* dump.c (dump_db): Update usage comment.  Add "-rev" and
	"-recurse" flags to permit reverse and recursive dumping of the
	database, respectively.  Check for dump filename beginning with
	"-" to avoid accidental dumps to such filenames.

	* kdb5_util.c (usage): Update to match reality, primarily by
	updating the "dump" usage, but also showing global options before
	the command, which is how they were being interpreted anyway.

	* kdb5_util.M: Update to match reality.  Document "-mkey_convert",
	"-new_mkey_file", "-rev", and "-recurse" options to "dump".
	Document "dump to stdout" behavior.  Show global options before
	the command.  Make some formatting fixes.  s/binary tree/btree/
	since the btree back end is actually an n-ary tree.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@14757 dc483132-0cff-0310-8789-dd5450dbe970