Add probe for Selenium WebDriver

Hey Seb,

I finally managed to add a probe for the newer Selenium WebDriver! (I have been "doing" this for two years ...)
I'm still missing a couple of things ('is_element_present' has to be handled differently, a sample ats, extensive testing, probably change the way methods are inspected) but I thought you might already take a look at it. I wasn't quite sure about the documentation, neither.
I changed from Google to Bing in the example because Google automatically loads the results page when typing a keyword (this makes in harder to click on the 'search' button).
I have quite a lot of time right now and I'm going to code a couple of features next (just in case you want to wait ...)
Bye,
Rolf