Follow selection after re-sort

[Nutzzz]

If, e.g., the user changes a game's rating while in rating-sort mode, the selection should move to the game's new position.

[Nutzzz]

Note the current workaround is to ask the user for a specific number when in rating-sort mode. Perhaps that should just always be the case (i.e., use one key rather than using +/- )?