webui: add checkbox selector to all idnode grids. Fixes #1473.

src/webui/static/app/idnode.js

@@ -611,6 +611,12 @@ tvheadend.idnode_grid = function(panel, conf)
     var delBtn  = null;
     var editBtn = null;
 
+    /* Selection */
+    var select = new Ext.grid.CheckboxSelectionModel({
+      singleSelect    : false
+    });
+    columns.splice(0, 0, select);
+
     /* Model */
     var idnode  = new tvheadend.IdNode(d);
     for (var i = 0; i < idnode.length(); i++) {
@@ -652,11 +658,6 @@ tvheadend.idnode_grid = function(panel, conf)
       columns         : columns
     });
 
-    /* Selection */
-    var select = new Ext.grid.RowSelectionModel({
-      singleSelect    : false
-    });
-
     /* Event handlers */
     store.on('update', function(s, r, o){
       var d = (s.getModifiedRecords().length == 0);