KDL 1.0.0 compliance for implementations

[zkat]

This is a tracking meta-issue to make sure all existing implementations are up to speed with 1.0!

• [x] kdl-rs: https://github.com/kdl-org/kdl-rs/issues/18
• [x] kdljs: https://github.com/kdl-org/kdljs/issues/6
• [x] kdl-rb: https://github.com/danini-the-panini/kdl-rb/issues/2
• [x] kdl-dart: https://github.com/danini-the-panini/kdl-dart/issues/1
• [x] kdl4j: https://github.com/hkolbeck/kdl4j/issues/3
• [ ] kdl-net: https://github.com/borland/kdl-net/issues/1
• [ ] kdl-php: https://github.com/kdl-org/kdl-php/issues/22

New implementations:

• [ ] Lua: https://github.com/kdl-org/kdl/issues/145
• [x] Elixir: https://github.com/kdl-org/kdl/issues/155
• [x] C: https://github.com/kdl-org/kdl/issues/160
• [ ] Go: https://github.com/kdl-org/kdl/issues/54
• [x] Python: https://github.com/tabatkins/kdlpy

Other bits:

• [x] VS Code: https://github.com/kdl-org/vscode-kdl/issues/4

[hkolbeck]

I spoke to @borland on Twitter and he'd like to wait on the Java update, then port the changes over to the .NET impl, which works for me.

[hkolbeck]

I believe kdl4j is compliant with the 1.0.0 spec as of these changes: https://github.com/hkolbeck/kdl4j/pull/4

@borland: I think the changes in that PR should be ready to port over, though they're more extensive than I'd hoped.

[danini-the-panini]

Starting work on updating the dart implementation: https://github.com/danini-the-panini/kdl-dart/pull/2

[djmattyg007]

I wouldn't be waiting on the original kdl-py implementation to be updated. Even in its current state, it's not compliant with the spec as it was written at the time. Better to just refer to kdlpy and cuddle.

[Patitotective]

I think kdl-nim is already compliant with KDL v1.0.0.

[zkat]

Since we have #372 now, I'm going to close this one.