Change Combining Mutations

[Kamikaze Mongoose]

When you go to combine mutations, it tells you (almost word for word here) to select the ones that you want to combine. Intuitively, that wouldn't mean de-selecting mutations to combine them, it would be selecting them to combine them. The way that it's set up now goes against the way these interactions are normally handled. I think everyone (especially newer players) would benefit from changing the combine mutations system.

When we select combine, all stored mutations should be unselected and the mutations you select should be the ones that you want to combine.