Made fixes on Dr. Bowman's instructions. I also noticed that some navbar code was not included in the individual Masher files for most of the units (the code that inserts the section heading graphic), so I added that to all of those files. This will most likely be missing from JMS files in other sections too, so watch out for this when making fixes elsewhere. It means that if you use the Masher to build a single file (or a unit), the exercises end up with one navbar graphic missing.