Made cmd_line_parser::print_options() print out some new lines at the

end so that the user doesn't have to print them.

dlib/cmd_line_parser/cmd_line_parser_print_1.h

@@ -151,6 +151,7 @@ namespace dlib
                 else
                     out << "\n" << wrap_string(this->element().description(),ml,ml);
             }
+            out << _dT(ct,"\n\n");
             this->reset();
         }
         catch (...)