GraphViz license

[Jens Rehsack <rehsack%googlemail.com@localhost>]

Hi,

as Greg suggested, here is an license which is rated as free by
http://www.fsf.org/licensing/licenses/index_html: GraphViz is distributed
under the 'Common Public License Version 1.0'.

This license is neither listed in licenses/ (which should be easy to change)
nor in DEFAULT_ACCEPTABLE_LICENSES.

What kind of licenses should be added to DEFAULT_ACCEPTABLE_LICENSES? All
GPL compatible? All Free (and who decides what is free and what is not)?

Am I allowed to add that license (in text form to licenses/) and to
DEFAULT_ACCEPTABLE_LICENSES?

Best regards,
Jens