[arch-releng] archiso license

[Tobias Frilling]

If we want the license to be a) as permissive as possible and b) legally
watertight, there a basically three licenses to choose from (dismissing for now
many, many lesser known):

  1. The ISC License
  2. The BSD License (3- or 2-clause)
  3. The MIT/Expat/X11 license

All three are GPL compatible and OSI, FSF and Copyfree approved and should
withstand legal actions. The ISC license is basically a modernized version of
the 2-clause BSD license and is the preferred license of the OpenBSD project
since 2003.