If task is terminated due to timeout or a kill task command, then that should be written in the error element of the history entry

Current Situation

1. If task is terminated due to timeout then the JobScheduler writes the following to the log:

   [ERROR]  SCHEDULER-272  Terminating task after reaching deadline <job timeout="30">
   [ERROR]  Z-REMOTE-122  Separate process pid=5468: Caller has killed process / zschimmer::com::object_server::Connection::pop_operation
   [ERROR]  SCHEDULER-202  Connection to task has been lost, state=ending: Z-REMOTE-122  Separate process pid=5468: Caller has killed process
   

   Only the last error message in the error element is added to the <show_job/> answer:

   SCHEDULER-202  Connection to task has been lost, state=ending: Z-REMOTE-122  Separate process pid=5468: Caller has killed process
   

2. If a task is terminated due to a kill task command then the JobScheduler writes the following to the log:

   [ERROR]  Z-REMOTE-122  Separate process pid=5468: Caller has killed process / zschimmer::com::object_server::Connection::pop_operation
   [ERROR]  SCHEDULER-202  Connection to task has been lost, state=ending: Z-REMOTE-122  Separate process pid=3536: Caller has killed process
   

   Only the last error message in the error element is added to the <show_job/> answer:

   SCHEDULER-202  Connection to task has been lost, state=ending: Z-REMOTE-122  Separate process pid=3536: Caller has killed process
   

Desired Behavior

1. The error element of a <show_job/> answer should be

   SCHEDULER-272  Terminating task after reaching deadline <job timeout="30">
   

2. The error element of a <show_job/> answer should be

   SCHEDULER-xxx  Terminating task after  <kill_task> command