Replace syn.js

[uuf6429]

If possible, use selenium action api for all cases.

If not, consider using a syn alternative (or if to complex, depend on syn) for old selenium.

[stof]

We could also make those methods unsupported if we cannot implement them without Syn. In practice, methods implemented with syn are only partially implemented (for instance, I'm not sure focus() actually moves the focus to the element before simulating a focus event)

[uuf6429]

(for instance, I'm not sure focus() actually moves the focus to the element before simulating a focus event)

I can only say that it worked well for focus-triggered pseudoelements - e.g. I've used it to display and test custom tooltips based on elementToBeFocus:focus::after. But I agree with the rest of the sentiment.