adding license and reference to license in package.json

Hello @don-neufeld,

Please review the following commits I made in branch 'artem-add-license'.

a82f5c85e277bbd31fa7a5f2181efb2e52772a82 (2013-08-21 15:21:50 -0700)
adding license and reference to license in package.json


R=@don-neufeld