Vote for dark title bar support under macOS

[hendriks73]

This isn't strictly an issue with nb-darcula, but the underlying JVM.

The JetBrains Java runtime recently added support for dark titles bars under macOS. There is a corresponding OpenJDK enhancement request, asking for a similar mechanism.

If you're eligible to vote in the OpenJDK bug database, please consider casting your vote and motivate others.

Thanks.