Core: Reset element styles when using custom highlight methods

When use a custom highlight functions which for example place the error
class in a different element (like Bootstrap form-group wrapper) this
element are not unhighlighted after resetForm.

Closes #1323

src/core.js

@@ -455,10 +455,18 @@ $.extend( $.validator, {
 			this.lastElement = null;
 			this.prepareForm();
 			this.hideErrors();
-			this.elements()
-					.removeClass( this.settings.errorClass )
-					.removeData( "previousValue" )
-					.removeAttr( "aria-invalid" );
+			var i, elements = this.elements()
+				.removeData( "previousValue" )
+				.removeAttr( "aria-invalid" );
+
+			if ( this.settings.unhighlight ) {
+				for ( i = 0; elements[ i ]; i++ ) {
+					this.settings.unhighlight.call( this, elements[ i ],
+						this.settings.errorClass, "" );
+				}
+			} else {
+				elements.removeClass( this.settings.errorClass );
+			}
 		},
 
 		numberOfInvalids: function() {

test/test.js

@@ -810,12 +810,36 @@ test( "resetForm()", function() {
 	var v = $( "#testForm1" ).validate();
 	v.form();
 	errors( 2 );
+	ok( $( "#firstname" ).hasClass( "error" ) );
 	$( "#firstname" ).val( "hiy" );
 	v.resetForm();
 	errors( 0 );
+	ok( !$( "#firstname" ).hasClass( "error" ) );
 	equal( "", $( "#firstname" ).val(), "form plugin is included, therefor resetForm must also reset inputs, not only errors" );
 });
 
+test( "resetForm() clean styles when custom highlight function is used", function() {
+	var form = $( "#testForm1clean" ),
+		e = $( "#firstnamec" );
+	form.validate({
+		highlight: function( element ) {
+			$( element ).hide();
+		},
+		unhighlight: function( element ) {
+			$( element ).show();
+		},
+		ignore: "",
+		errorClass: "invalid",
+		rules: {
+			firstnamec: "required"
+		}
+	});
+	e.valid();
+	ok( !e.is( ":visible" ) );
+	form.validate().resetForm();
+	ok( e.is( ":visible" ) );
+});
+
 test( "message from title", function() {
 	var v = $( "#withTitle" ).validate();
 	v.checkForm();