Merge CopyrightInformation class with the LicenseInformationClass

[goneall]

Propose merging the CopyrightInformation class with the LicenseInformationClass to simplify the model. It is very unlikely one would be present without the other.

Propose new class name of CopyrightLicenseInformation or IPInformation (IP being short for Intellectual Property)

[CASTResearchLabs]

it came from the SPDX 3.0 draft I received
no specific advice against changing this part

[goneall]

@iamwillbar any thoughts on the proposal?

[iamwillbar]

That SDPX 3.0 Draft was pretty early in the discussions and was more intended as a guide to direction than anything else. I agree that license information and copyright could be combined, however, there was some negative sentiment to calling it intellectual property, so we could just stick with LicenseInformation.

I know that one problem in SPDX that @tsteenbe (I think) wanted to resolve in 3.0 is having the ability to correlate copyright holders with each license. We should definitely consider that as part of this.