FU: Use schema validation for query parameters

...much better.

(Also I remembered why I threw away groff stderr; it's pretty useless)

ManUtils/ManUtils.pm

@@ -60,7 +60,7 @@ sub fmt($input) {
         if ($poll->events($err)) {
             my $r = sysread $err, my $buf, 16*1024;
             $poll->remove($err) if $r == 0;
-            warn "GROFF: $buf\n" if $r > 0;
+            #warn "GROFF: $buf\n" if $r > 0;
         }
     }
 }