Cleanup *GraphicsDevice: Use 'final' for ctor parameter; DefaultGraphicsDevice.getUniqueID(..) shall perform 'intern()' only once.
X11/WGL GLContext Impl: setGLFunctionAvailability(..) w/ withinGLVersionsMapping:=true if null == sharedContext

.. otherwise no quirk could be set on non ARB ctx GL implementations.

null == sharedContext, always for first context creation, i.e. indeed within GL version mapping.