Use EventFiringWebDriver to log WebDriver interactions and log getText() output

[OndraM]

Currently, we use custom inherited RemoteWebDriver implementation to log calls of execute().

However, php-webdriver provides EventFiringWebDriver, which allows registering custom listeners. This is much cleaner way how to accomplish the logging, it will also provides us the ability to register listener to events of EventFiringWebElement, so we can eg. log text returned from getText() calls.

So the aim is:

• Use EventFiringWebDriver and custom listener to provide current logging done by custom RemoteWebDriver
• Nice to have: Similarly add logging of output of text received using getText() calls (could be separated to different issue).