add after_shutdown hook

python/src/deltachat/account.py

@@ -522,6 +522,7 @@ class Account(object):
             deltachat.clear_context_callback(self._dc_context)
             del self._dc_context
             atexit.unregister(self.shutdown)
+            self._pm.hook.after_shutdown()
 
     def set_location(self, latitude=0.0, longitude=0.0, accuracy=0.0):
         """set a new location. It effects all chats where we currently

python/src/deltachat/hookspec.py

@@ -31,6 +31,10 @@ class PerAccount:
     def log_line(self, message):
         """ log a message related to the account. """
 
+    @account_hookspec
+    def after_shutdown(self):
+        """ Called when the account has been shutdown. """
+
     @account_hookspec
     def configure_completed(self, success):
         """ Called when a configure process completed. """

python/src/deltachat/tracker.py

@@ -38,6 +38,8 @@ class ConfigureFailed(RuntimeError):
 
 
 class ConfigureTracker:
+    ConfigureFailed = ConfigureFailed
+
     def __init__(self):
         self._configure_events = Queue()
         self._smtp_finished = Event()