This sample demonstrate how to build a custom module system, which is 
partially compatible with Node's own module system.
To try it, run the loader and provide it with a module name, as you were requiring
it from inside a module, for example:

node loader ./main.js

The command above will instrument our homemade module loader
to use 'main.js' as entry point. From that point on, all the modules
loaded will use our homemade version of 'require' instead of the
default one.

File description: 
- loader.js:  the homemade module loader
- main.js the entry point of the application
- moduleA, moduleB two modules to illustrates the functionality of our require