#38: latest slides

Please note: I also made changes to the view -- I added the class .latest-slides for the block and added the session class for the rows. This gives a little breathing room between the items.

You can check out some sample data in the block on Test: http://test-nyccamp2014.gotpantheon.com/, the block is at the bottom.
Merge pull request #147 from mirie/39_mirie_latest_slides

#38: latest slides