First go at editorial comments widget

This is the first go at fixing #120. It solves the following issues and adds some of the following functionality:
* Shows unpublished and published posts, makes visual distinction between two
* Shows editorial comments on posts your following
* Allows posting of comments on new stories
* Allows posting new or reply comments on editorial comments on posts
* Allows the viewing of an editorial comment conversation up to two parent comments
* Denotes the difference between new comments on a post and comments that are replies

Things to note:
* I ended up moving this widget to its own class just given the amount of extra functionality it required. Could probably crunch it all down into one function if that makes more sense.
*  I created an entirely new javascript object to handle the posting of comments and viewing of comment history from this widget. Could instead add this functionality to the existing javascript object for handling ajax comment posting, and just add that js file to this widget
* I ended up having to construct some odd sql query to fetch the comments that the user is following, given that I thought of it as the following logic: "Get all the recent comments on posts that the user is following." You could get recent comments or recent posts, but I couldn't see a way to use a standard function (get_post or get_comment), to get recent comments on posts that the user is following. "The user is following" is a bit of a curveball in terms of comment retrieval.
* The widget overall might have too much going on. I guess it would come down to whether people find it more worthwhile to be presented with all their recent "activity," instead of recent posts or recent comments in separate widgets (or toggled in some fashion). Not sure.