commit of version 2.1.0
handling of class file format 64 (Java 20) : modules, records, etc.
test : bug JDK 8136419 fixed in JDK 9
tests : config changed for Windows 10
BWD : config and code mishaps
added EMPTY_XXX_ARR, public isInPolygon()
BWD : mouse/wheel events : upgrade, and posInClient outside of client now properly allowed (was illegitimately constrained in, and inconsistently with posInScreen) or not (to handle edge cases due to scaling)
BWD impl : ScaledRectDrawer : box sampling is accurate rather than smooth