instead of the script line itself knowing that it points to something,
pull it down to the argument level, so that each argument knows
if it points to something.
This will allow a single script line to point to multiple things (like trainers pointing to multiple text or scripts)
* Allow battle scripts to _not_ add a new code body if the code body contains a subset of already found code.
* Allow battle scripts to include XXXXXX: labels for parts that have things pointing directly to them.
* Improve battle script parameter recognition.
battle scripts are almost identical to pokescripts in how they work. Each command has a single-byte code, followed by some number of arguments, each of which are 1 to 4 bytes.
Because of these similarities, we can reuse the same engine code and just load the engine from another file. So the code tool can have a 4th mode and basically just work for free. Runs for battle scripts can be as simple as XSE runs: just a single byte, don't bothe decoding, show decoding only in the tool.
Still to add: how to know which battle script commands are ending commands, or which ones point to other battle scripts, or which ones point to strings. How to view battle scripts in the editor? Etc.
