Issue: #336: Split "Administer comments"

Fixes issue #336. Assumes persons with "administer comments" permission should also be able to "administer comment settings" but not the reverse.
I think the intention was to not allow users that are moderators ('administer comments') allow to modify the comment settings. So perhaps this should simply be just 'administer comment settings' and not either/or? Tests should need to be adjusted to work with this new permission requirement.