Changes to Maia and Electra

The following changes have been made to the Electra and Maia feed aggregators:

• Added Johan Ålfeldt's Regnum Francorum Online
• Removed Greek and Roman Studies: IWU Student Posts from Abroad (feed generates 404, and so does the blog itself)
• Removed duplicate Compitum subscriptions
• Removed David Beard's Archaeology in Europe because the feed contains invalid tags