Share code for applying changes made by Lua scripts.
Fixed bogus stack access in Lua.
Fixed undo text for Lua curb tool.
Updated LuaScripting.html
ToLua name of LuaTileTool is TileTool, consistent with other class names.
Recreate LuaTileTool's LuaMap when BMP stuff changes.
WorldEdDock: double-clicking a lot opens it.
WorldLotTool: context menu shows "Open in TileZed" for cell maps, not just Lots.
tool-parking-stall.lua: self.xy -> self.x and self.y
BuildingEd: Added grid color to preferences.
PreferencesDialog: Added "default" button to reset the grid color.

Also fiddled with the layout.
Fixed crash with WorldLotTool when a WorldEd project was reloaded.
If an adjacent map is reloaded, put any WorldEd Lots back in it.