This is an informed attempt at reorganizing the engine/ directory by
creating categorized subdirectories, in order to make it easier to
navigate and find things.

The directories created are as follows:
* engine/game: Contains all "minigames", things like the unown puzzle
and slot machine.
* engine/gfx: Contains all handling of graphics. From loading palettes
to playing animations.
* engine/link: Contains all multiplayer functionality.
* engine/menu: Contains all generic/misc. menus and menu code.
Other, more specialized menus are in their own subdirectories (pokedex,
pokegear, party menu, etc).
* engine/overworld: Contains all handling of the overworld. From loading
and connecting maps to wild encounters and the scripting engine.
* engine/pokegear: In the same vein as engine/pokedex, except it could
use some more splitting up.
* engine/pokemon: Contains everything related to manipulating pokemon
data. From the pokemon storage system to evolution and mail.
* engine/printer: Contains everything related to printing things as well
as the printer communication.
* engine/title: Contains intro sequences, title screens and credits.

# Conflicts:
#	audio/engine.asm
#	constants/gfx_constants.asm
#	constants/map_data_constants.asm
#	constants/pokemon_data_constants.asm
#	constants/sprite_constants.asm
#	constants/wram_constants.asm
#	data/maps/data.asm
#	engine/battle/ai/scoring.asm
#	engine/battle/core.asm
#	engine/battle/effect_commands.asm
#	engine/battle/misc.asm
#	engine/battle_anims/getpokeballwobble.asm
#	engine/breeding.asm
#	engine/buy_sell_toss.asm
#	engine/decorations.asm
#	engine/events/battle_tower/battle_tower.asm
#	engine/events/battle_tower/rules.asm
#	engine/events/buena.asm
#	engine/events/bug_contest/contest_2.asm
#	engine/events/daycare.asm
#	engine/events/dratini.asm
#	engine/events/halloffame.asm
#	engine/events/happiness_egg.asm
#	engine/events/kurt.asm
#	engine/events/lucky_number.asm
#	engine/events/magnet_train.asm
#	engine/events/overworld.asm
#	engine/events/pokerus/pokerus.asm
#	engine/events/print_unown.asm
#	engine/events/print_unown_2.asm
#	engine/events/unown_walls.asm
#	engine/item_effects.asm
#	engine/link.asm
#	engine/mon_menu.asm
#	engine/player_object.asm
#	engine/routines/playslowcry.asm
#	engine/scripting.asm
#	engine/search.asm
#	engine/search2.asm
#	engine/specials.asm
#	engine/start_menu.asm
#	engine/timeset.asm
#	home/battle_vars.asm
#	home/map.asm
#	maps/GoldenrodUndergroundSwitchRoomEntrances.asm
#	maps/IlexForest.asm
#	maps/KrissHouse2F.asm
#	maps/Route39Barn.asm
#	mobile/mobile_12_2.asm
#	mobile/mobile_40.asm
#	mobile/mobile_5f.asm
#	wram.asm