Moved to facebook's new php webdriver

Biggest changes:

 * features:
   * move to facebook's PHP webdriver
   * support for `implicit_wait` (I know, discouraged, but sometimes useful)
 * refactored code:
   * setup
   * moved JS to external files
   * switched " with ' in JS code (less escaping parsing, less issues with Selenium2)

Is there any interest in integrating this? Otherwise, I'd maintain it myself as an additional mink driver.