Modified plex-log-saver.py, has better "daemon" mode.

plex-log-saver.py
- Script now runs as a simple daemon, checking every 1 minute.
- To shutdown, just touch a file named '__shutdown__'
- Script takes on average 1.5 seconds to execute on 7MB of log files.
- After 3 hours of running script uses an average of 10mb.