Provider testing improvements

New: Test button for indexers in UI

Fixed: Testing download clients shows error messages in UI
Fixed: Testing notifications shows error messages in UI

src/UI/Settings/ProviderSettingsModelBase.js

@@ -0,0 +1,36 @@
+'use strict';
+
+define([
+    'jquery',
+    'backbone.deepmodel',
+    'Shared/Messenger'
+], function ($, DeepModel, Messenger) {
+    return DeepModel.DeepModel.extend({
+
+        test: function () {
+            var self = this;
+
+            this.trigger('validation:sync');
+
+            var params = {};
+
+            params.url = this.collection.url + '/test';
+            params.contentType = 'application/json';
+            params.data = JSON.stringify(this.toJSON());
+            params.type = 'POST';
+            params.isValidatedCall = true;
+
+            var promise = $.ajax(params);
+
+            Messenger.monitor({
+                promise        : promise,
+                successMessage : 'Testing \'{0}\' completed'.format(this.get('name')),
+                errorMessage   : 'Testing \'{0}\' failed'.format(this.get('name'))
+            });
+
+            promise.fail(function (response) {
+                self.trigger('validation:failed', response);
+            });
+        }
+    });
+});