Title: fixed a couple of minor issues in call to notification scripts
Level: 1
Component: notifications
Compatible: compat
Version: 1.2.8p4
Date: 1464879023
Class: fix

The fixed issues are as follows:
 - in case of a timeout of the notification script, the script is supposed to be
   terminated. This worked only on python 2.6 and newer
 - due to timing there was a good chance the exit code of the notification script
   was ignored
 - the output of the notification script was buffered in memory until the process
   exited before being written. Theoretically this could cause high memory usage
   in the notification processes
