feat(taskList): limit drag and drop to handle

Author: johannesjo

app-src/scripts/task-list/task-list-d.html

@@ -12,7 +12,6 @@
 
     <div class="first-line"
          layout="row"
-         as-sortable-item-handle
          layout-align="space-between center">
       <md-button class="md-icon-button "
                  aria-label="is updated"
@@ -30,6 +29,7 @@
 
       <ng-md-icon class="handle"
                   flex="none"
+                  as-sortable-item-handle
                   icon="drag_handle"></ng-md-icon>
 
       <md-button class="md-icon-button play-btn"