Add filter for Custom Post Types

I know this looks like a mess - bear with me ;)

My editor auto-fixed a bunch of whitespace, so I broke that into a separate commit for you. It looks like some of your contributors mixed in 2-space indentation with your tab-based indentation. This was not all automated - I reviewed the indentation line by line to insure it was sane.

A new panel has been added to the admin page to list the types of posts available (including 'Blog Posts' and any custom post types that have been defined). Most of the ticker generation code remains the same - the queries just include a post_type argument.