Removed BasicCommand.GoBack method
Removed BasicCommand.GoBack method

Under remarks, the method said the following:
"There is a strong chance that this will be removed in the future."

The GoBack static method was originally added because KSMVVM's
BasicCommand class was from an internal-use MVVM toolkit. There is no
longer any need for such a helper method.

dustinleavins/KSMVVM.WPF