All: Drop remaining jQuery <1.8 workarounds

Ref jquerygh-2249

Author: mgol

ui/data.js

@@ -28,16 +28,10 @@
 "use strict";
 
 return $.extend( $.expr.pseudos, {
-	data: $.expr.createPseudo ?
-		$.expr.createPseudo( function( dataName ) {
-			return function( elem ) {
-				return !!$.data( elem, dataName );
-			};
-		} ) :
-
-		// Support: jQuery <1.8
-		function( elem, i, match ) {
-			return !!$.data( elem, match[ 3 ] );
-		}
+	data: $.expr.createPseudo( function( dataName ) {
+		return function( elem ) {
+			return !!$.data( elem, dataName );
+		};
+	} )
 } );
 } );

ui/effect.js

@@ -125,15 +125,6 @@ function styleDifference( oldStyle, newStyle ) {
 	return diff;
 }
 
-// Support: jQuery <1.8
-if ( !$.fn.addBack ) {
-	$.fn.addBack = function( selector ) {
-		return this.add( selector == null ?
-			this.prevObject : this.prevObject.filter( selector )
-		);
-	};
-}
-
 $.effects.animateClass = function( value, duration, easing, callback ) {
 	var o = $.speed( duration, easing, callback );
 

ui/widgets/datepicker.js

@@ -971,8 +971,7 @@ $.extend( Datepicker.prototype, {
 				$.datepicker._tidyDialog( inst );
 			};
 
-			// DEPRECATED: after BC for 1.8.x $.effects[ showAnim ] is not needed
-			if ( $.effects && ( $.effects.effect[ showAnim ] || $.effects[ showAnim ] ) ) {
+			if ( $.effects && ( $.effects.effect[ showAnim ] ) ) {
 				inst.dpDiv.hide( showAnim, $.datepicker._get( inst, "showOptions" ), duration, postProcess );
 			} else {
 				inst.dpDiv[ ( showAnim === "slideDown" ? "slideUp" :