Use lower case to be consistent with existing license names.
Declare that free/open licenses do not have -license at the end.
Better articulate rationale for default choice.
Add x11 license (also called mit).
Note 'wait and see' stance towards gnu-gpl-v3.
accepting the license"; that sounds too close to a contract issue.
Pkgsrc's license framework is merely about not building a package with
a license not on the ok list by accident, and is not intended to have
any contractual effects.
Split comment about 'package user" into separate concepts of
installing binary packages and running programs in packages.
Add XXX about how DEFAULT_ACCEPTABLE_LICENSES relates to the initial
value of ACCEPTABLE_LICENSES.
