Clean up modules listing

I'm trying to get the modules listing in admin/build/modules a little bit cleaned up.

Right now 'Node Images' is listed in the group Others, as there is no package info provided in node_images.info.

As this adds to the shattered listing we have at the moment, I propose moving the module to the already populated group "Image" (package = Image.)

If there is some support for it or at least no objection, I will provide a patch within the next days.