Add new mappings for numlock, numpadenter and numpadcomma on X11

[blaind]

• Tested on all platforms changed
• Compilation warnings were addressed
• cargo fmt has been run on this branch
• cargo doc builds successfully
• Added an entry to CHANGELOG.md if knowledge of this change could be valuable to users
• Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
• Created or updated an example program if it would help users understand this functionality
• Updated feature matrix, if new features were added or implemented

[ArturKovacs]

We are hoping to release the new keyboard API in the next version of winit, which should include all of these. So right now, I would instead encourage you @blaind, to join us in testing #1932, if you can.

[maroider]

We are hoping to release the new keyboard API in the next version of winit, which should include all of these.

I have half a mind to close this PR, #1266, #1846, and #1864 on this basis.

[ogoffart]

I think this could merged as-is. It is kind of trivial, and the small bug it fixes does not need to wait that the new keyboard API is finished.

[ArturKovacs]

Yeah we can merge this. @maroider do you have anything against this?

[ogoffart]

ping?

[maroider]

Welp, I completely forgot about this.

I don't have anything in particular against this, but I suspect you'll have to take some extra steps to ensure the changelog entry ends up in the right place.

[ArturKovacs]

@maroider good point. I suggest rebasing this on master.

[blaind]

@maroider good point. I suggest rebasing this on master.

Was about to rebase, but made a mistake and now too many commits are visible in the pull request. Will fix later today.

[maroider]

It looks like you did a merge instead of a rebase.

[blaind]

It looks like you did a merge instead of a rebase.

Should be fixed now. Based on the master branch & force-pushed