Release usable on recent JVM's

The Javascript Engine "Nashorn" was removed in newer JVM's. The Java code editor pane was relying on Javascript. I switched this to the new "Graal" scripting engine. For older JVM releases, this produces some error messages at startup, but except of being annying, being able to run the software on all JVMs (even on MacOS) is a clear benefit.

Further, please note that the size of GeckoCIRCUITS.jar increased a lot. This is due to the new packaging, which includes all libraries within a single "fat" jar file.

Release is published as pre-release, until some people tested it as being good. Then I will turn it into a real release.

Have fun with the software!
Andreas