Adding support for command directives, for example: '--nouse-idle-notification' and '--expose-gc' 

I added support for 2 important nodejs directives. The directives can be passed as follows:

<i>forever --noUseIdleNotification --exposeGC</i>

if the directives are explicitly specified, they are passed to the argument-list when spawning the node process. Currently there's no other way to pass these directives since they need to be placed before the js file name when spawning nodejs.

here's a reference to a discussion about this issue in [stackoverflow](http://stackoverflow.com/questions/12901358/starting-node-js-using-forever-with-nouse-idle-notification-and-other-flags)

The change is also reflected in the forever-monitor's [monitor.js](https://github.com/yairlev/forever-monitor/blob/master/lib/forever-monitor/monitor.js) file.