Grey out all other permissions when assigning the administrator permission

As the "Administrator" permission literally grants every permission available, I recommend greying out the rest (or putting them in a non-clickable-on-state) so that the user realises what is about to be done. This could also clear up any confusion regarding this role, as it (and I speak for myself) can get quite confusing to why some roles don't work as intended, only to realise the "administrator" one is checked. If the role overwrites every other role, why even let the user check the rest if it won't change anything.