Licence handling: next steps

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

I'd like to start adding license information to pkgsrc after 2009Q1 in
earnest.

The first part is better support in the infrastructure. The current
LICENSE variable is not flexible enough, because it only allows
choosing one license for a package. I extended the variable to support
AND and OR. The new syntax is: by default, all licenses in LICENSE are
ANDed together, you can specify OR by using the pipe symbol ('|')
without any spaces around.

Example:
        LICENSE=license1|license2 license3 license4
means that you have to accept
        (license1 OR license2) AND license3 AND license4
to build this package.

I think this should be sufficient for our needs; if not, we can
revisit it later.

The diff for supporting this is attached, the only user-visible change
is that bulk builders have to set _ACCEPTABLE to "yes" to skip the
license checks (until now, it sufficed to set it to anything).
I plan on committing this diff after 2009Q1.

The diff also adds a warning when building a package that doesn't have
LICENSE set.

The second step is adding/enabling LICENSE variables in the pkgsrc
Makefiles.
NOTE: Much care should be taken in this step -- rather leave it out if
you're not sure.

At some point in the future (perhaps after 2009Q3), setting the
LICENSE will not be optional for packages.

What is currently completely missing is handling of licenses when
installing binary packages, I hope someone else will provide this
part.

Comments?
 Thomas