Some major changes here.  Now any comparable type can be used for a key,
	 not just strings.  Takes advantage of this nice feature with golang
	 maps.  Added k-v pair level security.  So the hashed password of
	 each user is stored in the logbase itself, while each user also has
	 a map with keys corresponding to the master catalog and values
	 indicating CRUD permissions.  These maps are persisted in a new
	 "user" subdirectory, as files named for the user.  Numerous
	 fixes/improvements made.