Add some AngularJs commands based on protractor

I wrote some commands to help when the page has AngularJs.  I based it on https://github.com/angular/protractor, which is a module that enhances javascript webdriver with some Angular specific commands.  I just copied their client side script code and call it from haskell, it works great.

I offer this code here to see if you want to merge this into the core webdriver.  I could also put it in a new package called webdriver-ng or something.