Bug 845: Fix JNILibLoaderBase.addNativeJarLibsImpl(..) fat-jar case.

Always use the jar-basename when calling TempJarCache.addNativeLibs(..),
otherwise it is mapped and loaded multiple times leading to different native libraries.

Simplify addNativeJarLibsImpl(..) argument semantics by passing complete jarBasename
and nativeJarBasename (w/ suffix).

Added manual test scripts validating [gluegen + jogl] usage
with multi (Bug 843) and fat (Bug 845) jar configurations.