Each time a player find out something special you should call 'set_quest()'

Example:
	this_player()->set_quest("my_special_quest", 10);

  To set 'my_special_quest' done and reward it for 10 quest points.

If you use this on a quest that has all ready been rewarded, it will have
no effect.


Use query_quests() with questname as an argument to see if a player has
completed a quest. The call returns 1 if the quest is complete otherwise 0.

Example:
	this_player()->query_quests("my_special_quest", 10);


Examples for quest point distribution:

	1-4 quest points even for the simplest thing: figuring out a special
command. Could be just something seen in the long desc. To encourage
reading long descs.

	5-20 quest points for something a bit more complex, perhaps when
completing a serie of special commands in different places.

	10-25 quest points for giving some monster something it wants, that
you have to get elsewhere, maybe kill a monster for it.
