This introduces `def_script_pointers`, `def_text_pointers`, and `object_const_def` macros, and applies them to all maps. Most other map labels have also been identified.
* Update sign to bg_event #289
* Rename warp to warp_event
* Replace object to object_event
* Move warp macro parameter from warp x, y, id, map to warp_event x, y, map, id