[Admin] control panel for site admins

[murfguy]

Site Admins will need a space from which they can manage certain tasks and see information:

Admin Panel should feature:

• List of recent logins
• List of recent registrations
• Tools for approving/denying community creation requests
• Basic site analytics: streaming activity, user activity, etc.

[murfguy]

Added a tool for managing a user's site role. And added placeholders for other listed items.

[murfguy]

Can now approve/reject communities.

[murfguy]

Changed milestone to v0.4.

Can now quickly approve new community requests from the admin panel in addition to the full form.

For v0.4, a full summary view is planned for implementation.