Changes 12/17/14

Did EIMACS Test 21 with Sam.  It wasn't too hard, they had a lot of inserting into priority queues, then popping off the values in various ways.

I guess that in my last post, I didn't realize that the purpose of the exercise they gave me was to re-implement these ADT methods, even though they already existed.  However, that was not made clear, and so someone who is familiar with the ADT (which would hopefully be the people following the curriculum) would probably be confused by the fact that they are overriding this list functionality with identical methods.