Bf 312 improve select handling

initially i wanted to change only the handling of selects, but then i had to replace splinter with selenium in many files. which is good, because it's on the TODO list anyway.

so this pr covers:
* BF-312 use selenium selects
* BF-330 correct slowly type
* start to get rid  of splinter
* more test coverage
Why not to remove `three` here? If anybody will modify it, he'll forget to change it :)