Script and plot file to make a simple two-line gnuplot graph.
Usage is simple. Produce a file of the following format:
<epoch timestamp> <value> <epoch timestamp> <value>
<epoch timestamp> <value> <epoch timestamp> <value>
<epoch timestamp> <value> <epoch timestamp> <value>
...
Then run ./multiplot.sh data-filename NameOfLine1 NameOfLine2 NameOfGraph