progress with avoidance of global Configuration access
eliminated last calls to Configuration.getInstance()
new package io.csg
extracted file loading concerns from STLObject ...

into a new class STLFileLoader
reduced cross packet dependency
moved static methods to the class they are used in
established package dependencies without circular dependencies
removed unused methods (get/setUnique)
refactored radicalReOrder

extracted the different cases as methods
don't skip polygons to join in radicalReOrder