Fix races / finally remove global app for good (#7570)

* finally remove global app for good

* test compilation fixes

* fix races

* fix deadlock

* wake up write pump so it doesn't take forever to clean up

app/email_batching_test.go

@@ -14,6 +14,7 @@ import (
 
 func TestHandleNewNotifications(t *testing.T) {
 	th := Setup()
+	defer th.TearDown()
 
 	id1 := model.NewId()
 	id2 := model.NewId()
@@ -94,6 +95,7 @@ func TestHandleNewNotifications(t *testing.T) {
 
 func TestCheckPendingNotifications(t *testing.T) {
 	th := Setup().InitBasic()
+	defer th.TearDown()
 
 	job := NewEmailBatchingJob(th.App, 128)
 	job.pendingNotifications[th.BasicUser.Id] = []*batchedNotification{
@@ -201,6 +203,8 @@ func TestCheckPendingNotifications(t *testing.T) {
  */
 func TestCheckPendingNotificationsDefaultInterval(t *testing.T) {
 	th := Setup().InitBasic()
+	defer th.TearDown()
+
 	job := NewEmailBatchingJob(th.App, 128)
 
 	// bypasses recent user activity check
@@ -237,6 +241,8 @@ func TestCheckPendingNotificationsDefaultInterval(t *testing.T) {
  */
 func TestCheckPendingNotificationsCantParseInterval(t *testing.T) {
 	th := Setup().InitBasic()
+	defer th.TearDown()
+
 	job := NewEmailBatchingJob(th.App, 128)
 
 	// bypasses recent user activity check
@@ -281,6 +287,8 @@ func TestCheckPendingNotificationsCantParseInterval(t *testing.T) {
  */
 func TestRenderBatchedPostGeneric(t *testing.T) {
 	th := Setup()
+	defer th.TearDown()
+
 	var post = &model.Post{}
 	post.Message = "This is the message"
 	var notification = &batchedNotification{}
@@ -306,6 +314,8 @@ func TestRenderBatchedPostGeneric(t *testing.T) {
  */
 func TestRenderBatchedPostFull(t *testing.T) {
 	th := Setup()
+	defer th.TearDown()
+
 	var post = &model.Post{}
 	post.Message = "This is the message"
 	var notification = &batchedNotification{}