Multiple url support, CLI parsing module and dynamic build

Pretty massive update.

I hope you like the build of `penthouse.js`. It retreives the values from `package.json` so that they are always in sync. No more manually updating the preamble :-) 

The CLI parsing is now done by a separate module. 

And there is also support for multiple urls. If you just pass one then it functions the same as before. But the order of the css and url had to change, so that is a breaking change.

fixes #10
From **getCssAndWriteToFile()** (in the root `penthouse.js`):

```
//we're done, log the result as the output from phantomjs execution of this script!
fp.write(cleanup(css));
```
So if I run the penthouse.js script with phantomjs, standalone from the command line.. then it will still write to file, right? And not do what the instructions say? Or am I missing something?