Rake

Yo, I don't know why it says I deleted and then added all that stuff in tumblr.rb back. Basically, I just added an if clause in all the types to make sure there aren't any duplicates. For tumblr.rb that necessitated the addition of post.url to all posts, regardless of type; without that, there was no way of identifying unique tumblr posts. Let me know if that's a problem!