Item constants in trainer ai.
Move trainer item AI into battle/ai/items.asm.
Name and comment the trainer party reader.

Reads the contents of trainers/trainers.asm.
Makefile: Use lower-case variables and graphics conversion queues.

This is mostly to make it more like pokered.

Queues are an order of magnitude faster than invoking a new python instance for each file.
Name and comment some move learning functions.
Use a predef macro that takes labels instead of juggling constants.

Besides making predefs convenient, naming a predef no longer requires
adding or renaming a predef constant. This also lets predefs be rearranged at will.