add hyperxmp option

[TeXhackse]

As described in #69 this PR adds the hyperxmp boolean option, which is initialized to true. The default behaviour won't change, except if pdfx has been loaded before doclicense.

An additional option to disable/enable the automatic setting of the metadata is not necessary, I added a hint to the corresponding warning, that one would have to manually adjust this. The \hypersetup variant is not compatible to pdfx as is requests an xmdata-file.

I was a bit confused if I should already add the sty-file but since you seem to be tracking this with eery commit, I did as well.

[ypid]

Thanks, merged.

I was a bit confused if I should already add the sty-file but since you seem to be tracking this with eery commit, I did as well.

Thanks for the hint. I reconsidered now and dropped the sty files from being tracked by git.

[zhtaihao]

@TeXhackse Thank you for drafting this PR, seems like a great addition.

@ypid Any estimate on when we can expect this update to be on CTAN/Sharelatex?

[ypid]

I usually wait a few weeks before I release new features. As now 3 people are involved in this feature, there is some level of review so what do you say when I release it on Friday 2021-03-12?

[ypid]

It has been released on Monday, ref: https://ctan.org/ctan-ann/id/[email protected]. I took a few hours on Saturday to work on the package a bit before releasing it. With the release, can #69 be closed?

[TeXhackse]

Yup, @ypid. thank you.