It would be handy to have the ability to run Java files with separate mains from with a NetBeans module project.  I can
think of the following used cases.

1. As a module developer I'd like to run or debug a single file so I can quickly execute a file in a way that I think
will reproduce a bug I'm trying to fix.
2. As a module developer I might like to add some benchmarks to some classes in my module.
3. As a module developer I might like to reuse my file types or data model to generate some data files.   

Steps to Reproduce

1. Create Module project.
2. Create Java File with main method.
3. Compile Java File
4. Right click on file in project explorer.

"Run file" menu item is disabled.  It should be enabled.