Allow set message and title by String too

[WKnak]

The moment we ask users to rate our App is very important, should be done nicely and in a not-disturbing way. To try to engage people, I want to set message in runtime, not only by StringRes id. So if I have a logged in customer, I want to show something like:

"Hello, William! Today we want to ask you a few seconds of your time to bla bla bla..."

This can be easily achieved by allowing access to Config object creating a .setMessage(String message) public method!