Add ability to pass arguments and change the executable path

Hi,

   I have added two new arguments: ```execPath``` and ```scriptArgs```.

   - __execPath__ allows to change the path of Node.js. Convenient to run Coffeescript scripts
   - __scriptArgs__ can be use to pass arguments to a Node.js script

   You will also find a change that prevent the creation of ```<script>_error.log``` and ```<script>-error.log``` files

   Please tell me if you want two different Pull Requests. 
   Or anything you want me to change really :)

Thank you for this excellent project

Aurélien