isaac, crcsync: acknowledge licensing issues.

isaac, crcsync: acknowledge licensing issues.

The recently added ccanlint licensing checks revealed several cases
where the published license of a module is misleading: a dependency of
that module has a stricter license (eg. a public domain module which
depends on a GPL one).

Where these are my modules, I've fixed them.  Otherwise I'm overriding
the checks for the moment, and asking the authors what they want to do.