(svn r16909) -Fix [FS#2996]: NewGRF stations would be triggering assertions all over the place when using the more advanced station types.

-Change: make (rail) waypoints sub classes of 'base stations', make buoys waypoints and unify code between them where possible.

src/ai/api/ai_waypointlist.cpp

@@ -13,7 +13,7 @@ AIWaypointList::AIWaypointList()
 {
 	const Waypoint *wp;
 	FOR_ALL_WAYPOINTS(wp) {
-		if (wp->owner == _current_company) this->AddItem(wp->index);
+		if (wp->facilities & FACIL_TRAIN && wp->owner == _current_company) this->AddItem(wp->index);
 	}
 }