[ADF-1729] Mark Files and Folders as Favorite (#2466)

* favorite nodes

* removed fdescribe

* use Output over CustomEvent

* EventEmitter any

docs/node-favorite.directive.md

@@ -0,0 +1,83 @@
+# Node Favorite directive
+
+Selectively toggle nodes as favorite
+
+<!-- markdown-toc start - Don't edit this section.  npm run toc to generate it-->
+
+<!-- toc -->
+
+- [Basic Usage](#basic-usage)
+  * [Properties](#properties)
+  * [Events](#events)
+- [Details](#details)
+
+<!-- tocstop -->
+
+<!-- markdown-toc end -->
+
+## Basic Usage
+
+```html
+<adf-toolbar>
+    <button md-icon-button
+            (toggle)="done()"
+            [adf-node-favorite]="documentList.selection">
+    </button>
+</adf-toolbar>
+
+<adf-document-list #documentList ...>
+ ...
+</adf-document-list>
+```
+
+```ts
+@Component({
+    selector: 'my-component'
+})
+export class MyComponent {
+
+    done() {
+        // ...
+    }
+
+}
+```
+
+### Properties
+
+| Name              | Type                | Default | Description                 |
+| ----------------- | ------------------- | ------- | --------------------------- |
+| adf-node-favorite | MinimalNodeEntity[] | []      | Nodes to toggle as favorite |
+
+### Events
+
+| Name                      | Description                                  |
+| ------------------------- | -------------------------------------------- |
+| toggle                    | emitted when toggle favorite process is done |
+
+## Details
+
+The `NodeFavoriteDirective` instance can be bound to a template variable through **adfFavorite** reference,
+wich provides a method to help further style the element.
+
+```html
+<button
+    md-menu-item
+    #selection="adfFavorite"
+    [ngClass]="{ 'icon-highlight': selection.hasFavorites() }"
+    [adf-node-favorite]="documentList.selection">
+    <md-icon [ngClass]="{ 'icon-highlight': selection.hasFavorites() }">
+        {{ selection.hasFavorites() ? 'star' : 'star_border' }}
+    </md-icon>
+</button>
+```
+
+The directive performs as follows:
+
+- if there are no favorite nodes in the selection, then all are marked as favorites
+- if there is at least one favorite node in the selection, then only those who are not
+  are being marked
+- if all nodes in the selection are favorites, then they are removed from favorites
+
+
+See **Demo Shell**