Add an admin to the Whitelister Role

[levino]

Fix #1585: Make whitelister role ownable and give the owner power to remove all other whitelisters.

It is debatable whether or not this should be added to official codebase. I would also be very happy to get a review on this specifically considering security implications.

[levino]

I understand why you closed this. A quick feedback on whether or not this code is possibly problematic for the security of the SC would have been much appreciated though.

[nventuro]

At a glance, I don't see any security issues, though the implementation is incomplete: you should also remove entries from bearers on _remove calls, and you may want to perform some extra checks via require.

Additionally, since you're iterating over an array, removeAll may end up being too expensive to call in a single block: adding some sort of 'pagination' would help in this regard.

[levino]

Cool, thanks. Removing a bearer twice or thrice is not a problem, that is why I did not reset the bearers array. But the point with the loop is valid. Do you have an example for this pagination? It is not possible to just overwrite the whole array with an empty one, right? Thank you for your review!