Automatically find new enemy data offset if a level is edited that shares enemy offsets with another level

[opsodps]

To see what I mean, do the following:

1. Load the 1-1 bonus room (the room with the coins that spell out "3").
2. Add any enemy or item into it and save.
3. Now load into the 1-2 bonus room (the long vertical room with coins at the bottom) and you'll see the items/enemies you placed in 1-1 there as well.

This applies to other levels too, these are just the earliest/easiest to access ones in the game. I probably don't need to explain why this should be fixed.

[mchlnix]

Maybe this is wanted though. I guess an additional save dialog should appear with "save", "cancel" and "separate enemies"?

Could be annoying, if you want them to stay connected, and have to click on save everytime, but then again, with instaplay there isn't that much need to save?

[mchlnix]

Conversation on Discord:

Michael: Hammer Bro levels, I guess. But looking at all the free space in the enemy PRG, there's really no reason to even have shared enemy data.
...
Michael: True. I'll think of something. Another save dialog would be kinda lame, but then again, as you say, since there's no real reason to share enemies, one click on separate and it doesn't pop up anymore.

Michael: I don't want to automate the possibility away, since I want to stay as close to the ROM as possible and allow as much as possible. Will see.