Add new information about processing method to perunRequest

 - add endTime and result to perunRequest object
 - change behavior of saving perunRequests, GET will not be saved, PUT
   and POST yes
 - when call ends, save endTime and result to perunRequest if is PUT or
   POST type
 - when some request ends, remove all requests older than defined time
   from list of pending requests
 - set exception to result only if caller throw this exception