File loading.

This should fix #129.
It loads the file.
However, when you go to import a module, it doesn't seem to properly resolve it.

For instance, this happens:

```
> :m ~/programming/purescript-json/src/Data.JSON.purs
> :i Data.JSON
> fromString "{\"a\": 2}"
  
Error in import declaration Data.JSON:
Module Data.JSON does not exist
> 
```

It has the file loaded and module available in the list of modules, so I assume this is some thing else going on.
Although, it could be putting these modules in the wrong place, but Prelude is loaded the same way so I'm not too sure.