Cleanup GPL License

@RoganDawes,

I inserted the text that is to be replaced within the GPL https://github.com/cmlh/OWASP-WebScarab/commit/a0dff40f2c30e4ab022d115a0269ce98ede5f4ac

I have added a LICENSE.md file as per https://help.github.com/articles/open-source-licensing#how-can-i-go-back-through-my-public-repositories-and-give-them-licenses