Update CONTRIBUTING.md

Updated CONTRIBUTING.md to specify that the `this` keyword should be avoided.
Fixes #35: Solution file should be located in the root of the repository
Update README.md
Update README.md
Update README.md
Update README.md

Add links to Google Groups and JabbR
Update README.md

Add a link to the samples repository
Remove samples directory
Merge branch 'master' of github.com:scriptcs/scriptcs

* 'master' of github.com:scriptcs/scriptcs:
  Update README.md
Merge branch 'master' into dev