removed faob commands from general demo commands

ps-grammar/commands/commands.jsgf

@@ -10,7 +10,4 @@ public <statement> = [tobi] [please] <command> [please] [tobi];
 <door> = recognize [a] door;
 <leave> = leave | go back | we are done;
 <finish> = lets call it a day;
-<locate> = ( ( where is [a | an | the] ) | ( where are [the] ) ) <object>;
-<list> = ( which objects do you know ) | ( list [the] objects );
-<object> = ( milk | apple | box );
-<observe> = (observe | start observing | take a look );
+<observe> = (observe | start observing );