Add button to reload extension if update pending

For #522

options/options.js

@@ -20,6 +20,9 @@
 	const mobile = require("../lib/mobile");
 	
 	const callbacks = {
+		reloadExtension: function(){
+			browser.runtime.reload();
+		},
 		openNavigatorSettings: function(){
 			logging.verbose("open navigator settings");
 			window.open("navigator.html", "_blank");

options/settingsDisplay.js

@@ -19,6 +19,11 @@
 						{
 							"name": "disruptSessionOnUpdate"
 						},
+						{
+							"name": "reloadExtension",
+							"actions": ["reloadExtension",],
+							"displayDependencies": [{"updatePending": [true]}]
+						},
 					]
 				},
 				{