Creative Commons Licensing for edX

This PR adds Creative Commons Licensing to the Open edX Platform.
Also you will need to i18n everything. Please do not put html within i18n if possible (see https://github.com/edx/edx-platform/wiki/i18n-Coding-Guidelines). This one for example, please do
`u"<p>" + _("This resource is not licensed.") + u"</p>"`