Organize the engine/ directory, director's cut

Cleaned up `engine/routines`, in favor of moving files into more
appropriate directories. predef-related routines are now in top-level
`engine`.
`rtc/delete_save_change_clock.asm` has been split into both
`menus/delete_save.asm` and `rtc/reset_password.asm`.

Made a new subdirectory:
* engine/math: Contains all generic math-related routines.

engine/link/initlist.asm

@@ -0,0 +1,54 @@
+InitList: ; 50db9
+	ld a, [wInitListType]
+
+	cp INIT_ENEMYOT_LIST
+	jr nz, .check_party_ot_name
+	ld hl, wOTPartyCount
+	ld de, wOTPartyMonOT
+	ld a, ENEMY_OT_NAME
+	jr .done
+
+.check_party_ot_name
+	cp INIT_PLAYEROT_LIST
+	jr nz, .check_mon_name
+	ld hl, wPartyCount
+	ld de, wPartyMonOT
+	ld a, PARTY_OT_NAME
+	jr .done
+
+.check_mon_name
+	cp INIT_MON_LIST
+	jr nz, .check_item_name
+	ld hl, wCurMart
+	ld de, PokemonNames
+	ld a, MON_NAME
+	jr .done
+
+.check_item_name
+	cp INIT_BAG_ITEM_LIST
+	jr nz, .check_ob_item_name
+	ld hl, wNumItems
+	ld de, ItemNames
+	ld a, ITEM_NAME
+	jr .done
+
+.check_ob_item_name
+	ld hl, wCurMart
+	ld de, ItemNames
+	ld a, ITEM_NAME
+.done
+	ld [wNamedObjectTypeBuffer], a
+	ld a, l
+	ld [wListPointer], a
+	ld a, h
+	ld [wListPointer + 1], a
+	ld a, e
+	ld [wUnusedD102], a
+	ld a, d
+	ld [wUnusedD102 + 1], a
+	ld bc, ItemAttributes
+	ld a, c
+	ld [wItemAttributesPtr], a
+	ld a, b
+	ld [wItemAttributesPtr + 1], a
+	ret