Adding testUtils and parallel tests base classes

I refactored all the common test logic we use in many projects in this one. I also deprecated some classes we do not use anymore (should we simply delete the UiHandlers stuff?)
I also added the necessary classes to run multiple selenium+cucumber tests in parallel. The rest is done in the maven configuration of the project using this library. I still need to write some doc (will do that once I update our projects with parallel tests, since I'll have a better idea of what is required).

Feel free to improve this ;)