Fix 202 tutorial. You can't name a column 'Show Scope' because angula…

…r pukes over the binding. that will be addressed later in some binding fixes

misc/tutorial/202_externalScopes.ngdoc

@@ -35,7 +35,7 @@ Then in a template, you access the scope using getExternalScopes() function.
        $scope.gridOptions.columnDefs = [
              { name: 'firstName' },
              { name: 'lastName'},
-             { name: 'Show Scope',
+             { name: 'ShowScope',
                  cellTemplate:'<button class="btn primary" ng-click="getExternalScopes().showMe()">Click Me</button>' }
            ];