Added 'PCLCrypto' to Libs/C#
Added 'HElib' to Libs/C++
Added 'crypto-algorithms' to Libs/C
Added 'Subreddit of Cryptography' to Web-sites
Added 'A Graduate Course in Applied Cryptography' to Books
Added 'Journey into cryptography' to Courses
* added list of libs and frameworks
* minor changes
* added c#
* minor
* Create CONTRIBUTING.md
* minor
* added twitter and web-sites
* removed twitter from resources
* Added 'Resources' and few new links.
Changed the `CONTRIBUTING.md` file to suite the current workflow.
Added new `dependency` in `package.json` to validate links. But it is not quite working yet.