pull_client: save not sent results on service stop
pull_client: don't fail on bad DLP URL
pull_client: pyflakes ignore
pull_client: don't start polling if there is still results to be sent

If all remaining results are not sent the incomming commands are not in sync
with what has been done on the client. So wait to send all results then start
polling for commands.
dlp: adjust logging configuration
scheduler: DLP query - max_failures equal to remaining attempts
core: Remove debug messages
report: Hide Others if there is no other to display
scheduler: dlp - target_awake - return False if machine not detected
scheduler: return False to dlp in case of error
scheduler: more robust test to check if command is failed
scheduler: return remaining attempts for the command to DLP