Relicense to GPLv3+ with wide exception for all Free Software / Open Source projects + Business options.

Nexedi stack is licensed under Free Software licenses with various exceptions
that cover three business cases:

- Free Software
- Proprietary Software
- Rebranding

As long as one intends to develop Free Software based on Nexedi stack, no
license cost is involved. Developing proprietary software based on Nexedi stack
may require a proprietary exception license. Rebranding Nexedi stack is
prohibited unless rebranding license is acquired.

Through this licensing approach, Nexedi expects to encourage Free Software
development without restrictions and at the same time create a framework for
proprietary software to contribute to the long term sustainability of the
Nexedi stack.

Please see https://www.nexedi.com/licensing for details, rationale and options.

- Nexedi adheres to GPLv3+ with wide exception for Free/Open-source
  software. Use this for our original work.

- Zodbanalyze was initially developed by Zope corp & co. See

  d86d04dc	(initial copy of ZODB3-3.9.7's ZODB/scripts/analyze.py.)
  ab17cf2d	(Hook in Nexedi's zodbanalyze)

  So follow original Zope's licensing terms for zodbanalyze.