[patch] Add -i=mi0 as an interpreter

[Andrew Cagney]

> We must update gdb.texinfo to reflect this change.  It currently
> documents only -i=mi.

Ok.  It turns out I also need to juggle the file names (DOS 8.3).

> Why can't this strncmp be done in one place and then saved in some
> variable?  If you do need to use strncmp all over the place, then I
> can't say I care to see the magical constants "mi" and 2 every time
> you do ;-)



True. While still not good will at least be consistent.  Perhaps I'll 
call the function mi_out_p_but_i_wish_this_hack_would_just_go_away() :-) 
(deprecated_mi_out_p()).

	Andrew