Add obsoleted-by attribute

[goneall]

Creating an issue to track a variation on a proposal made by @wking in the [https://github.com//pull/392](ecos pull request).

Proposal: Add attribute to license and exception "obsoleted-by" to reference a license expression which should be used in place of a deprecated license. This attribute would only be valid if deprecated=true.

[wking]

On Tue, May 30, 2017 at 11:11:07AM -0700, goneall wrote: This attribute would only be valid if deprecated=true.

I wouldn't have a ‘deprecated’ attribute in the XML source, although I'm fine with it getting injected into compiled output. More details in [1]. [1]: #392 (comment)

[bradleeedmondson]

references #392

[bradleeedmondson]

Discussed on legal call June 8, 2017. We like adding this information, but are not planning on doing so for the next release. Will leave this issue open for consideration & possible implementation in future release.

[wking]

On Thu, Jun 08, 2017 at 10:52:25AM -0700, Bradlee H. Edmndson wrote: We like adding this information, but are not planning on doing so for the next release.

Removing the ‘deprecated’ attribute from the source (like I'd like to do) will be a breaking change for anyone consuming the source XML. So if we intend to make that attribute part of the first XML-based release, I'd recommend a warning marking the attribute as potentially unstable.

[goneall]

Let's leave this issue open to track. I'm still of the opinion we should retain the deprecated attribute, but we can discuss and resolve on the next release. If needed, I can write another conversion utility to update the licenses to a new format.

[wking]

We can close this now that #392 has landed. Dropping the deprecated attribute (also discussed above) is tracked by the in-flight pull request #583.

[goneall]

@wking agree - closing the issue. The tools have been updated to output compatible JSON and RDF formats of the license.