Added replace parameter for setText

Requires https://github.com/admc/wd/pull/333 to be pulled first.

I also want to create a test for this in keyboard-specs.js but I can add that in another pull. 

Tested with the wd.js change and it works for me.
@austenke It's a good practice to always suspect your data, especially when dealing with types or data structures generated dynamically from strings, e.g. json, objects deserialized from xml, etc.