license: relicense to copyleft-next

A pending patch suggests copyleft-next GPLv2 compatible,
it integrates the license as the list of possible licenses
used on modules and files [0] in the Linux kernel. While
integration of this patch is pending, relicense this userspace
code to copyleft-next in the meantime. copyleft-next is my
license of choice.

The current template license on tables.h is temporary while
its sorted out what is best.

As noted in the proposed patch upstream to add copyleft-next to
the list of kernel compatible licenses [0] but added here to explain
*why* I've decided to do this, a summary of benefits of using
copyleft-next >= 0.3.1 over GPLv2 is listed below, it shows *why*
some folks like myself will prefer it over GPLv2 for future work.

An obvious gain not in that list is that this particular userspace
code is now under copyleft-next, so while GPLv2 applies to the Linux
kernel we benefit from keeping this code under copyleft-next if
future enhancements are made upstream on the Linux kernel.

o It is much shorter and simpler
o It has an explicit patent license grant, unlike GPLv2
o Its notice preservation conditions are clearer
o More free software/open source licenses are compatible
  with it (via section 4)
o The source code requirement triggered by binary distribution
  is much simpler in a procedural sense
o Recipients potentially have a contract claim against distributors
  who are noncompliant with the source code requirement
o There is a built-in inbound=outbound policy for upstream
  contributions (cf. Apache License 2.0 section 5)
o There are disincentives to engage in the controversial practice
  of copyleft/ proprietary dual-licensing
o In 15 years copyleft expires, which can be advantageous
  for legacy code
o There are explicit disincentives to bringing patent infringement
  claims accusing the licensed work of infringement (see 10b)
o There is a cure period for licensees who are not compliant
  with the license (there is no cure opportunity in GPLv2)
o copyleft-next has a 'built-in or-later' provision

[0] http://lkml.kernel.org/r/1465929311-13509-1-git-send-email-mcgrof@kernel.org

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
4 files changed