Hours per week label

I added an "hours per week label" to the schedule page UI. I figured this would give students an easier and more accurate method of counting up their weekly hours rather than doing it manually. 

Here is a screenshot of the changes I made to the UI:
![newui](https://cloud.githubusercontent.com/assets/6456601/4179941/768239c4-36dd-11e4-9b65-c5f656a19971.png)

What is this for? The code should be agnostic to the fact that a lot of Waterloo courses end at 11:20 or 11:50, if this is doing what I think it is.

Instead of accumulating whole hours here, it is much simpler and accurate and easier to reason about by accumulating minutes as the total, then divide by 60 and round outside of the while loop.