[gentoo-licenses] handling copyright attribution in licenses that require it

[Mike Frysinger]

if you want to utilize the LICENSE variable in ebuilds to help with licensing 
compliance, you quickly run into issues with the licenses that require 
explicit copyright attribution.  specifically, the BSD and MIT family of 
licenses.  this clause is the annoying part:
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

since all of the ebuilds point to the same stock file (e.g. licenses/BSD) 
which has this stock header:
	Copyright (c) <YEAR>, <OWNER>
the file is not sufficient for automatically producing a file that covers all 
packages in a compliant manner.

in Chromium OS, we're attacking the problem in two ways:
	- during build (when all the source is available), scan for copyright 
owners and save the results into the vdb
	- allow for people to override on a per-package basis in the 
licenses/copyright-attribution/ subdir

the first option would be nice to integrate into portage, but there are going 
to be cases where it either cannot find all the right answers (because the 
source doesn't correctly state it), or might find too many wrong answers 
(unused source files with outdated names).  so we're going to want to 
integrate this somehow on a per-ebuild basis.  metadata.xml might work, but 
doesn't work well with something that can change across ebuild $PVR's.  so 
maybe something like a new LICENSE_COPYRIGHT variable that can be a scalar or 
array.

has anyone else been looking at this ?  or have thoughts on how to tackle the 
problem in a non-sucky way ?
-mike