Trainer data structure and field move functions

Trainer data in map scripts is now a macro-defined structure.

Field move functions in main.asm are now nearly completely annotated, with local references.

Trailing white space deleted.

constants/item_constants.asm

@@ -354,3 +354,13 @@ const_value SET 70
 	const HELD_BRIGHTPOWDER
 	const HELD_4E
 	const HELD_FOCUS_BAND
+
+	const_def
+	const ITEMATTR_PRICE
+	const ITEMATTR_PRICE_HI
+	const ITEMATTR_EFFECT
+	const ITEMATTR_PARAM
+	const ITEMATTR_PERMISSIONS
+	const ITEMATTR_POCKET
+	const ITEMATTR_HELP
+NUM_ITEMATTRS EQU const_value