Speed-up compilation when working on tilemanager.
#include <Main/viewer.hxx>
#include <Scenery/scenery.hxx>
-#include <Scenery/tilemgr.hxx>
#include "AIEscort.hxx"
#include <Main/viewer.hxx>
#include <Scenery/scenery.hxx>
-#include <Scenery/tilemgr.hxx>
#include <Airports/dynamics.hxx>
#include "AIGroundVehicle.hxx"
#include <GUI/new_gui.hxx>
#include <GUI/dialog.hxx>
#include <Aircraft/replay.hxx>
-#include <Scenery/tilemgr.hxx>
#include <Scenery/scenery.hxx>
#include <Scripting/NasalSys.hxx>
#include <Sound/sample_queue.hxx>
#include <Model/acmodel.hxx>
#include <Scenery/scenery.hxx>
#include <Scenery/redout.hxx>
-#include <Scenery/tilemgr.hxx>
#include <GUI/new_gui.hxx>
#include <Instrumentation/HUD/HUD.hxx>
#include <Environment/precipitation_mgr.hxx>