Lots of changes to support compilation under Qt 5.1.1.
Fixed crash with WorldLotTool.
Fixed missing argument types in tolua.c.
Ported worldreader.cpp changes from WorldEd.
Fixed crash with MapComposite's handling of mKeepFloorLayerCount.
BuildingEd: Tool fixes and improvment to SelectMoveRoomsTool.

BuildingDocument now manages the current room selection region.
BuildingBaseScene gained a RoomSelectionItem to display the room selection.
Previously, SelectMoveRoomsTool maintained and displayed the selection.

SelectMoveRoomsTool gained a cursor item.

Fixed the current tool being forgotten when switching to/from WelcomeMode.
Fixed BuildingMap's BmpBlender not being updated when a building resized.
Use BuildingRoomDefecator when highlighting the room under the mouse pointer.
BuildingEd: Added "Crop To Selection".