fix(android-2.2): use dot notation for reserved 'class' keyword

Closes #1228

Author: ajoslin

js/angular/directive/itemDeleteButton.js

@@ -40,7 +40,7 @@ IonicModule
     compile: function($element, $attr) {
       //Add the classes we need during the compile phase, so that they stay
       //even if something else like ngIf removes the element and re-addss it
-      $attr.$set('class', ($attr.class || '') + ' button icon button-icon', true);
+      $attr.$set('class', ($attr['class'] || '') + ' button icon button-icon', true);
       return function($scope, $element, $attr, ctrls) {
         var itemCtrl = ctrls[0];
         var listCtrl = ctrls[1];

js/angular/directive/itemOptionButton.js

@@ -34,7 +34,7 @@ return {
   require: '^ionItem',
   priority: Number.MAX_VALUE,
   compile: function($element, $attr) {
-    $attr.$set('class', ($attr.class || '') + ' button', true);
+    $attr.$set('class', ($attr['class'] || '') + ' button', true);
     return function($scope, $element, $attr, itemCtrl) {
       if (!itemCtrl.optionsContainer) {
         itemCtrl.optionsContainer = angular.element(ITEM_TPL_OPTION_BUTTONS);

js/angular/directive/itemReorderButton.js

@@ -52,7 +52,7 @@ IonicModule
     require: ['^ionItem', '^ionList'],
     priority: Number.MAX_VALUE,
     compile: function($element, $attr) {
-      $attr.$set('class', ($attr.class || '') + ' button icon button-icon', true);
+      $attr.$set('class', ($attr['class'] || '') + ' button icon button-icon', true);
       $element[0].setAttribute('data-prevent-scroll', true);
       return function($scope, $element, $attr, ctrls) {
         var itemCtrl = ctrls[0];