Customisation features

I added some custom class/method naming functionalities based on what is doing the selenium ide's bundled "Java / Junit 4 / Webdriver" format (@see webdriver.js and remoteControl.js in the original selenium-ide.xpi).

- Dynamic class and test method name generation based on the filename
- New configuration option to choose the phpuint class (so you can use a custom phpunit class of your own)

Tested locally.
Please review and pull if you like.