Cleanup GPLv3 License

I inserted the text that is to be replaced within the GPLv3 i.e. https://github.com/cmlh/EJSF/commit/62475eb59bcebfbd120363e450f57e286fe1eb7d

I have copied the LICENSE file as LICENSE.md too as per https://help.github.com/articles/open-source-licensing#how-can-i-go-back-through-my-public-repositories-and-give-them-licenses