Licensing confusion in jxlayer code

[hyandell]

Describe the bug
Licensing appears to have been lost in the embedded jxlayer code

Additional Information:
The darklaf jar contains the file PBJAR_LICENSE.txt, which indicates the code is under the combination of a couple of BSD-3-Clause licenses and an LGPL-2.1 license from Oracle. The Oracle reference appears to come from SwingX - of which this is a copy someone has made public https://github.com/certusoft/swingx/blob/master/swingx-core/src/main/java/org/jdesktop/swingx/ForwardingRepaintManager.java

Looking at the Darklaf code, this appears to be the source for the https://github.com/weisJ/darklaf/blob/master/core/src/main/java/org/pbjar/jxlayer/repaint/WrappedRepaintManager.java file. It's hard to ascertain though because all of the jxlayer's code has had its copyright replaced with the darklaf source header (it's unusual to see copyright statements removed, but perhaps you had the permission from each of the copyright holders).

Does this LGPL-2.1 for WrappedRepaintManager.java mean the darklaf-core jar should be treated as LGPL-2.1?