docs(ngModel): align $viewValue description with $setViewValue

Author: Narretz

src/ng/directive/ngModel.js

@@ -22,7 +22,9 @@ var ngModelMinErr = minErr('ngModel');
  * @ngdoc type
  * @name ngModel.NgModelController
  *
- * @property {string} $viewValue Actual string value in the view.
+ * @property {*} $viewValue The actual value from the control's view. For `input` elements, this is a
+ * String. See {@link ngModel.NgModelController#$setViewValue} for information about when the $viewValue
+ * is set.
  * @property {*} $modelValue The value in the model that the control is bound to.
  * @property {Array.<Function>} $parsers Array of functions to execute, as a pipeline, whenever
        the control reads value from the DOM. The functions are called in array order, each passing