star kwargs and kwargs for say function

[brainysmurf]

Using mutable objects for default keyword arguments can result in hard-to-find bugs; beginners will likely find it to be a rabbit hole. So I suggest changing kwargs={} to the standard **kwargs.

Also, for the say function, it might be a good idea to think of it as a tricked-out print function; the print function has useful keyword arguments such as end, so added **kwargs to say.