refactor(item): removed ItemGroup directives

references #636

ionic/components/item/item-group.ts

@@ -1,50 +0,0 @@
-import {Directive, ElementRef, Host, Optional, NgZone} from 'angular2/angular2';
-import {Content} from '../content/content';
-import {throttle} from '../../util/util';
-import {position, offset, CSS, raf} from '../../util/dom';
-import {Config} from '../../config/config';
-
-/**
- * TODO
- */
-@Directive({
-  selector: 'ion-item-group',
-  host: {
-    'class': 'item-group'
-  }
-})
-export class ItemGroup {
-  /**
-   * TODO
-   * @param {ElementRef} elementRef  TODO
-   */
-  constructor(elementRef: ElementRef) {
-    this.ele = elementRef.nativeElement;
-  }
-}
-
-/**
- * TODO
- */
-@Directive({
-  selector: 'ion-item-group-title',
-  host: {
-    'class': 'item-group-title',
-    '[class.sticky]': 'isSticky'
-  }
-})
-export class ItemGroupTitle {
-  /**
-   * TODO
-   * @param {ElementRef} elementRef  TODO
-   */
-  constructor(
-    private elementRef: ElementRef,
-    private zone: NgZone,
-    config: Config,
-    private content: Content
-  ) {
-    // make sure the sticky class gets set on the title
-    this.isSticky = true;
-  }
-}