﻿version 1.0, 2012-07-08 -- initial release

version 1.01, 2012-07-09 -- edited README

version 1.1, 2013-02-20 -- reset_units() runs on first import, and corresponding
changes to documentation. Also, don't mess up the random number generator
state, in case something else is using it. Added units pW, fF, aF.
