Added links to the Puzzle Code and Sidenote projects.

See: https://github.com/mikegagnon/puzzlecode
See: https://github.com/mikegagnon/sidenote
Added a link to Mike Gagnon's 'I Just Unlicensed My Software' post.

See: http://mikegagnon.com/2013/09/30/i-just-unlicensed-my-software/