uv3 slf4j simple logger can't be cast to locationaware logger

building jcasgen-maven-plugin was working by itself, but failing in Maven build of entire uimaj sdk. Eventually discovered after a day of poking around, and improving a diagnostic in core uima for UIMAFramework where it was trying to load the factory configuration, and getting an exception during class initialization (the improvement: print the exception), found out that the full build ended up having slf4j "simple logger" in the class path that was being used, and slf4j was hooking this up as its back-end. But this logger doesn't implement the location-aware interface, so a cast to that was failing. Fix this to no longer require this.