Make "isModified(true) on change" behavior optional

src/api.js

@@ -90,9 +90,7 @@
 		ko.utils.arrayForEach(array, function (observable) {
 			// Do not collect validatedObservable errors
 			if (utils.isValidatable(observable) && !observable.isValid()) {
-				// Use peek because we don't want a dependency for 'error' property because it
-				// changes before 'isValid' does. (Issue #99)
-				errors.push(observable.error.peek());
+				errors.push(observable.error());
 			}
 		});
 		return errors;

src/configuration.js

@@ -21,6 +21,7 @@ var defaults = {
 		live: false		    //react to changes to observableArrays if observable === true
 	},
 	validate: {
+		setModifiedOnChange: true, // enables setting `isModified(true)` when observable changes
 		// throttle: 10
 	}
 };