Browserify API broken

Hi,
there have been vast changes in the Browserify API, e.g. look at:

*exports in line 6/index.js*
https://github.com/substack/node-browserify/commit/04cc3b6a44610df8401e5d1c89d26ff29cd8420e#index.js

I have updated this plugin so It works again on my machine,
especially fixing these Issues:
* Browserify now is not initialized with options but with files
* A buffer can not be created from a stream

*This is my first time working with node.js streams so could you please have a look if used the api badly. Also this definitly should by tested by someone else again.*