[m-rev.] diff: delete XXX from std_util interface

[Zoltan Somogyi]

On Mon, 29 Dec 2014 15:32:42 +1100 (AEDT), Julien Fischer 
> library/std_util.m:
>  	Delete an XXX comment regarding alternative syntax for
>  	compose/3 from the interface to this module -- it shows
>  	up in the library reference manual otherwise.

If you replaced the XXX with NOTE_TO_IMPLEMENTORS,
it wouldn't. I recently added a filter for this to doc/Mmakefile.

Zoltan.