Mentions and hints

Fixed

• @greed ban, @greed fm and every other command run by mentioning greed no longer also post the "greed's prefix for this server" card. The card only shows when you mention greed on its own.
• The docs button on every /configure page now opens the matching docs page. Nine of them led to a page that did not exist.

Changed

• greed points prefix users to the slash version of a command a little more often. It still shows at most once every 3 days per person and once every 20 minutes per channel.