Use constants for menu flags

Added a bunch of constants for the bitflags of each kind of menu. Some
are slightly vague or too long, but I'm not sure how to else name them.

engine/events/kurt.asm

@@ -84,7 +84,7 @@ Kurt_SelectApricorn: ; 88055
 ; 88086
 
 .MenuDataHeader: ; 0x88086
-	db $40 ; flags
+	db MENU_BACKUP_TILES ; flags
 	db 01, 01 ; start coords
 	db 10, 13 ; end coords
 	dw .MenuData2
@@ -94,7 +94,7 @@ Kurt_SelectApricorn: ; 88055
 	db 0
 
 .MenuData2: ; 0x8808f
-	db $10 ; flags
+	db SCROLLINGMENU_DISPLAY_ARROWS ; flags
 	db 4, 7
 	db 1
 	dbw 0, Buffer1
@@ -159,11 +159,12 @@ Kurt_SelectQuantity: ; 880c2
 ; 8810d
 
 .MenuDataHeader: ; 0x8810d
-	db $40 ; flags
+	db MENU_BACKUP_TILES ; flags
 	db 09, 06 ; start coords
 	db 12, 19 ; end coords
-
-	db 0, 0, -1, 0 ; XXX
+	dw NULL
+	db -1 ; default option
+	db 0
 
 .PlaceApricornName: ; 88116
 	call MenuBoxCoord2Tile