minor tweaks to alert tab

public/app/features/alerting/partials/alert_tab.html

@@ -1,5 +1,5 @@
-<div class="panel-option-section__body">
-	<div class="edit-tab-with-sidemenu" ng-if="ctrl.alert">
+<div class="panel-option-section__body" ng-if="ctrl.alert">
+	<div class="edit-tab-with-sidemenu">
 		<aside class="edit-sidemenu-aside">
 			<ul class="edit-sidemenu">
 				<li ng-class="{active: ctrl.subTabIndex === 0}">
@@ -177,10 +177,12 @@
 			</div>
 		</div>
 	</div>
+</div>
 
-	<div class="gf-form-group" ng-if="!ctrl.alert">
-		<div class="gf-form-button-row">
-			<button class="btn btn-inverse" ng-click="ctrl.enable()">
+<div class="gf-form-group p-t-4 p-b-4" ng-if="!ctrl.alert">
+	<div class="empty-list-cta">
+		<div class="empty-list-cta__title">Panel has no alert rule defined</div>
+			<button class="empty-list-cta__button btn btn-xlarge btn-success" ng-click="ctrl.enable()">
 				<i class="icon-gf icon-gf-alert"></i>
 				Create Alert
 			</button>

public/app/features/dashboard/dashgrid/PanelEditor.tsx

@@ -53,7 +53,7 @@ export class PanelEditor extends PureComponent<PanelEditorProps> {
         return <GeneralTab panel={panel} />;
       case 'queries':
         return <QueriesTab panel={panel} dashboard={dashboard} />;
-      case 'alerts':
+      case 'alert':
         return <AlertTab angularPanel={angularPanel} />;
       case 'visualization':
         return (

public/sass/base/_icons.scss

@@ -221,11 +221,11 @@
     background-image: url('../img/icons_#{$theme-name}_theme/icon_advanced.svg');
   }
 
-  .gicon-alerts-active {
+  .gicon-alert-active {
     background-image: url('../img/icons_#{$theme-name}_theme/icon_alerting_active.svg');
   }
 
-  .gicon-alerts {
+  .gicon-alert {
     background-image: url('../img/icons_#{$theme-name}_theme/icon_alerting.svg');
   }