MikeHeiber/Ising_OPV: v4.0.0 Final Release

This is the final stable release of Ising_OPV v4.0.0 that will soon be published in the Journal of Open Source Software. This release only changes documentation files and does not contain modifications to the operation of the source code. For a detailed account of the changes, please see the Changelog. This release was developed under the financial assistance award 70NANB14H012 from U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD)