docs: Dual license under CC BY-SA and the GFDL

[cgwalters]

Originating issue: #1431

Mailing list post: https://mail.gnome.org/archives/ostree-list/2018-January/msg00004.html

---

This will allow the text to be used in Wikipedia for example; it
also just makes more sense for documentation than the LGPLv2+.

[cgwalters]

(Don't merge yet - I need to send out a "relicensing ok?" email to people)

[cgwalters]

@grimthorpe You are included in this due to 596fc29 - is this OK with you?

[jlebon]

I do not object. :)

[marcusfolkesson]

I think we also should add a SPDX identifier[1] tag to the license text.

E.g.
SPDX-License-Identifier: (CC-BY-SA-3.0 AND GFDL-1.3+)

When on it, we should also add the SPDX-identifier for COPYING file.
Do you want me to send a separate patch for SPDX-identifier on COPYING?

edit:
Actually... we should replace licence-text in all source files with
SPDX-License-Identifier LGPL-2.0+.
I will fix this later today if noone here thinks it is a bad idea.

[1] https://spdx.org/sites/cpstandard/files/pages/files/using_spdx_license_list_short_identifiers.pdf

[cgwalters]

@marcusfolkesson Makes sense, I'll update this PR for the docs. As for the source - before you do the PR, just so I know: does that involve touching every source file or just the COPYING? And is there a public example of a project doing that?

[cgwalters]

I'm not a SPDX expert but isn't it OR not AND here?

[marcusfolkesson]

@cgwalters
Yes, I think we should replace the license text in every source file with the identifier.
Example on projects that is doing this is: Linux kernel, U-Boot, Barebox, Buildroot and so on.

e.g.
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/tree/drivers/usb/core/driver.c?h=v4.14.15

And yes, it is OR as you suggest, I was a little too fast...

[cgwalters]

OK how about this for a footer?

Licensing for this document:

SPDX-License-Identifier: (CC-BY-SA-3.0 OR GFDL-1.3-or-later)

[blixtra]

Kinvolk is fine with the OStree documentation it holds rights to being relicensed CC-BY-SA-3.0 AND GFDL-1.3+

[wmanley]

Relicensing is fine by me

[maxamillion]

+1 to Relicensing

[miabbott]

+1 to Relicensing

[cgwalters]

OK, lifting WIP. The only people who haven't replied only have single line changes, which definitely falls under the ">= 10 lines" = "copyright" heuristic.

[cgwalters]

Just for my own future reference, the man/ directory probably should have been covered here, but we can do that later.

[jlebon]

@rh-atomic-bot r+ c5c6ed6

[rh-atomic-bot]

⌛ Testing commit c5c6ed6 with merge 79b3e22...

[rh-atomic-bot]

💥 Test timed out

[jlebon]

@rh-atomic-bot retry

[rh-atomic-bot]

⌛ Testing commit c5c6ed6 with merge 0211fa7...

[rh-atomic-bot]

💔 Test failed - status-atomicjenkins

[jlebon]

@rh-atomic-bot retry

[rh-atomic-bot]

⌛ Testing commit c5c6ed6 with merge 85c3164...

[rh-atomic-bot]

☀️ Test successful - status-atomicjenkins
Approved by: jlebon
Pushing 85c3164 to master...