[arch-dev-public] licenses: GPL permutations

[Paul Mattal]

What is the right way to list all the various contortions you can now 
have of GPL in the license array? There's:

GPL - any version of GPL
GPL2 - only version 2
GPL2+ - version 2 or later
GPL3 - version 3 only
GPL3+ - version 3 or later

These are all substantively different (except the last two.. for now) so 
how do we express these? Should we actually create common licenses GPL2+ 
and GPL3+ which reference the other two, and make GPL reference them 
all? Do we need a GPL1 and GPL1+?

- P