[Developers] Blog properties and ping idea

[Patrick Tufts]

A blog type could have the following properties:

- blog author(s)
- name
- blog url
- first post (date)
- last post (date)

and perhaps some property like "subject" or "top tags."

Blog author (co-typed as person) could have the following properties:

- name
- blogs

If you really wanted to go nuts, you could also catalog individual blog
posts (title, date, permalink) and link to these from both blog and blog
author.

--Pat