As title states. ManageWikiPermissions already has just about everything in it, but it does not currently have the ability to manage the revoked permissions array. Additionally, $wgRestrictionTypes is already in ManageWikiSettings, but RestrictionLevels is not. These two should go together.
Note: I may try to submit a patch for this myself when I have a good amount of time (which I haven't had lately), but I'm still filing this task in case someone wants to get to it first, and also because I'm not 100% confident that I know what I'm doing with this.