comment changes, spelling fix to graph, added testing code

No significant functional changes
Added commented out code to download files from internet
Made significant changes to the commenting of code.
Made "kilowat" spelling fix in code to plot1.png
added testing "source" code to top of each script and all four combined
at the bottom of plot1.R
Retested and verified all scripts run correctly on cloned version on
seperate box
post assignment todo: add code to unzip file and make creation of files
completely automated with one single call/more reproducable