Add cc-by-sa / free cultural works buttons

Project:web site
Component:User interface
Category:feature request
Priority:minor
Assigned:Unassigned
Status:active
Project wiki:How to use this web site
Description

Add where appropriate buttons from:
http://creativecommons.org/licenses/by-sa/3.0/
http://freedomdefined.org/Logos_and_buttons

link to:
http://freedomdefined.org/