Added ability to debug JavaScript source files through NetBeans / IntelliJ

Hi Tim,

I modified the module loading to work with Nashorn debugging support through "load" native function.
I successfully tested on NetBeans with local and remote debug.
However IntelliJ 13.1+ Ultimate claims to have Nashorn debugging support, I couldn't test.
Besides I patched "require" function a little bit to work with coffee scripts.