Add an admin interface for inserting the site-wide data

[JoeKennedy]

This includes:

• Characters
• Species
• Houses
• Series
• Episodes
• Events
• Blurbs

It could also include Actions and FAQ if they're moved into the database, and Blog posts once they're added. This would help in managing all these entities, and would simplify the user-facing views. Not if/then logic for whether or not to display forms.

If an admin plugin/library exists (though a preliminary search a few months ago did not produce one), we could probably use that, or we could write our own. However, just implementing an admin interface for our site, rather than writing a whole library and using that, would be fine.

In the future, it might be good to add all tables, including all the league-specific ones, to the admin interface, to prevent someone (usually me) from having to go into the DB to make minor changes, which is never a great idea, but right now is necessary in a lot of cases. But for this issue an admin interface for the tables/entities listed above is fine.