feed tree: add category context menu entry to un/collapse it

js/FeedTree.js

@@ -156,6 +156,12 @@ require(["dojo/_base/declare", "dijit/Tree", "dijit/Menu"], function (declare) {
 				var menu = new dijit.Menu();
 				menu.row_id = bare_id;
 
+				menu.addChild(new dijit.MenuItem({
+					label: __("(Un)collapse"),
+					onClick: function() {
+						dijit.byId("feedTree").collapseCat(this.getParent().row_id);
+					}}));
+
 				menu.addChild(new dijit.MenuItem({
 					label: __("Mark as read"),
 					onClick: function() {