Fixed a minor copy-and-paste-style bug in read_tower_data(). Does not
affect data generation or invalidate earlier data in any way.
Removed a pause in thesis_figures.m so it will run without requiring
user oversight.
Fixed a bug where read_tower_data() had been partially renamed to parse_tower_data(). It is now back to being called read_tower_data().
Added a file which will plot a 2-D histogram of the number of TV
channels received vs. the population density across the United States.