Removed unnecessary template member methods from TranformationFacade
* neither the constructor nor the generate member methods need to be templatized
** only supported "output" argument is now a reference to a "std::basic_ostream<char>" instance
** the caller is responsible for e.g. writing the output to disk
* this was done to simplify the basic interface of InputXSLT
* removed "default_params" testcase along with default parameter generation
** this feature is neither used nor required