Automatically Add/Remove Meta Data text when adding/removing Genre, Developer, Publisher, etc Hubs

[redwizard42]

When adding or removing a relevant meta data hub, it would be beneficial for it to automatically add that meta data to the existing meta data if not already present. Likewise, if removing a hub it would be nice if it could remove that meta data if present. Unrelated text in the meta data should be preserved.

I'm suggesting this realizing that hubs may change forms from magic game pages to something more proper, but I suspect the issue of adding the 'hub' and having the meta data text not be entered will persist. This is mostly an issue when viewing game lists on site and having the genre, etc not shown in that list because someone added the hub but not the relevant text. (It may also help in the future with querying data for DevQuest sweeps).