Implement sub-tree sharing; read-only pages

src/app/app.component.html

@@ -10,7 +10,7 @@
       <ion-content>
         <ion-list>
           <ion-list-header>
-            <ion-buttons class="ion-padding-start">
+            <ion-buttons>
               <ion-button fill="outline" [color]="refreshingMenu ? 'success' : 'light'" (click)="onMenuRefresh()">
                 <ion-icon color="tertiary" name="refresh"></ion-icon>
               </ion-button>
@@ -23,6 +23,9 @@
               <ion-button fill="outline" color="light" (click)="onDeleteClick()" [disabled]="!deleteTarget">
                 <ion-icon color="danger" name="trash"></ion-icon>
               </ion-button>
+              <ion-button fill="outline" color="light" (click)="onNodeMenuClick($event)" [disabled]="!menuTarget">
+                <ion-icon color="dark" name="more"></ion-icon>
+              </ion-button>
             </ion-buttons>
           </ion-list-header>