added ability to add links, description and images for lobbyists and corporations (via admin), and display them

Resolves #230 - 

You can add links via the admin to either lobbyists or lobbyist corporations. Can add description to lobbyist and lobbyist corporations and images for lobbyists.

All this metadata is also displayed on the site, currently, I didn't work too much to make it look good, once we get some data there we can look into what's the best way to display it.