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.
The proper fix for this is defining a better get method so we don't have to add logic each time a param is fetched. The server could use some general clean up.