Cleaning up code

In preparation for turning in the code, I started adding some comments
to the functions that I wrote, and I also got rid of some outdated
comments.

I also moved some of the buttons around on the toolbar to make things
look a little more even. (Humberto, if you get the input indication
text working, feel free to move things back around in order to make
room)

Finally, I added some instructional text at the bottom.