Refs #4 - Added CC-BY 3.0 License.
Refs #4 - Updated AUTHORS. Generated list of contributors with 'make authors'. Using git mailmap feature to duplicate author names/emails.
Refs #4 - Using the offline text for CC BY 3.0.
Refs #4 - Shown 'CC BY 3.0' license in footer.
Merge pull request #15 from benoitbryon/4-license

Refs #4: CC BY 3.0 license