Organize the engine/ directory, take 3

Renamed `title` to `movies`.
Moved some functions from `engine/routines/` to their fitting
directories, and cleaned up the base `engine/` directory.
Moved `engine/pokemon/tmhm.asm` back to `engine/items/`.

Made a new subdirectory:
* engine/tilesets: Contains all map-related graphics routines.

engine/menus/savemenu_copytilemapatonce.asm

@@ -0,0 +1,77 @@
+SaveMenu_CopyTilemapAtOnce: ; 4cf45 (13:4f45)
+	ld a, [hCGB]
+	and a
+	jp z, WaitBGMap
+
+; The following is a modified version of CopyTilemapAtOnce.
+	ld a, [hBGMapMode]
+	push af
+	xor a
+	ld [hBGMapMode], a
+	ld a, [hMapAnims]
+	push af
+	xor a
+	ld [hMapAnims], a
+.WaitLY:
+	ld a, [rLY]
+	cp $60
+	jr c, .WaitLY
+
+	di
+	ld a, BANK(vBGMap2)
+	ld [rVBK], a
+	hlcoord 0, 0, wAttrMap
+	call .CopyTilemapAtOnce
+	ld a, BANK(vBGMap0)
+	ld [rVBK], a
+	hlcoord 0, 0
+	call .CopyTilemapAtOnce
+.WaitLY2:
+	ld a, [rLY]
+	cp $60
+	jr c, .WaitLY2
+	ei
+
+	pop af
+	ld [hMapAnims], a
+	pop af
+	ld [hBGMapMode], a
+	ret
+
+.CopyTilemapAtOnce: ; 4cf80 (13:4f80)
+	ld [hSPBuffer], sp ; $ffd9
+	ld sp, hl
+	ld a, [hBGMapAddress + 1]
+	ld h, a
+	ld l, 0
+	ld a, SCREEN_HEIGHT
+	ld [hTilesPerCycle], a
+	ld b, 1 << 1
+	ld c, LOW(rSTAT)
+
+.loop
+rept SCREEN_WIDTH / 2
+	pop de
+.loop\@
+	ld a, [$ff00+c]
+	and b
+	jr nz, .loop\@
+	ld [hl], e
+	inc l
+	ld [hl], d
+	inc l
+endr
+
+	ld de, BG_MAP_WIDTH - SCREEN_WIDTH
+	add hl, de
+	ld a, [hTilesPerCycle]
+	dec a
+	ld [hTilesPerCycle], a
+	jr nz, .loop
+
+	ld a, [hSPBuffer]
+	ld l, a
+	ld a, [hSPBuffer + 1]
+	ld h, a
+	ld sp, hl
+	ret