Considering dual-license as GPLv3 and Apache2.0

[mpenning]

For a few years now, it's become apparent that my choice of GPLv3 in 2007 was fine back then, but now seems like time to consider offering under Apache2.0. Evidence:

• Napalm removed its dependencies on ciscoconfparse because of GPLv3
• See CiscoConfParse issue #105 requesting Apache license
• In 2016, a Cisco SW manager and other members of his team emailed me to request CiscoConfParse re-license under Apache
• Cisco maintains its own internal copy of CiscoConfParse (I never asked why, but GPLv3 is a very likely reason)
• Countless other informal requests for the same.

This github issue will document my investigation into dual-license CiscoConfParse as GPLv3 and Apache 2.0 license. If you are a PR submitter listed below, please leave comments if you object... cc anyone who opened PRs that were accepted (regardless of number of LoC):

• @jgsawyers
• @ragzilla
• @0racle
• @markonen
• @bnavigator

I am not a lawyer. If the community knows of a problem with dual license as described above, please comment.

[mpenning]

I am not going to re-license; there are commercial solutions to this problem; contact me through github issues. Also see the README...

If it's truly a problem for your company, there are commercial solutions available
(to include purchasing the project, or hiring me).