Trim pre- and post-amble in the CC-BY license text

[jeffmcaffer]

Why:

The CC-BY license file has extra text that is not intended to be part of the license itself.
See #275

closes #275

What's being changed:

Trim the extraneous text with guidance from the legal team.

[jeffmcaffer]

Need to validate that the new text is properly detected by licensee. Hold off merging until validated.

[zeke]

Looks good. Thanks for working on this 👍🏼

[jeffmcaffer]

Turns out that licensee does NOT detect this new text correctly. I chatted briefly with @benbalter and opened licensee/licensee#464. Two choices here:

1. merge this now. The user experience will likely be the same in that they should still see View license and should still be guided to the LICENSE file.
2. wait for the licensee fix.
3. close this as won't fix. The text is not invalid, it's just "overly complete"

I have no preference one way or another.

[mlinksva]

The repo UI isn't going to state a specific license regardless of what happens with this PR due to #204 (LICENSE-CODE is intelligible to humans, but licensee conservatively sees that and LICENSE and doesn't assert anything for the repo overall).

I would not recommend merging this. Most of the text cut is recognized to be optional, but is in the canonical version provided by CC, and in general I'd discourage fiddling with license texts merely to save a few bytes.

[jeffmcaffer]

I was intending on proposing some updates to the GitHub UI that would add support for showing multiple licenses. in that case, the licensee output (having found both LICENSE and LICENSE-CODE) could be rendered usefully. The overall outcome is NOASSERTION but there is a list of high confidence licenses that could be rendered.

In any event, since currently licensee does not recognize the trimmed down text, I suggest not merging this. Once licensee does, we can reconsider.

[chiedo]

In any event, since currently licensee does not recognize the trimmed down text, I suggest not merging this. Once licensee does, we can reconsider.

Sold!