* bin/service.py (loadConfig, Service.__init__): Rename shadowed builtin variables.
* bin/update-environment.py (read_env_d): Rename shadowed builtin variables.
* bin/mudur.py:
  Comment the code,
  Rename some functions for better self-explanation,
  Split setupUdev() to setupUdev() and startUdev(),
  Make the code pychecker clean.
* bin/mudur.py (loadFile, writeToFile):
  Use open() instead of file().
* bin/mudur.py (setupUdev):
  Limit the size of /dev to 10M,
  No need to traverse /lib/udev/devices, just copy it recursively,
  Remove uevent_helper hack for older kernels.
* bin/mudur.py (startUdev):
  Use start-stop-daemon for udev monitor startup/cleanup.
* bin/mudur.py (stopSystem):
  Call stopUdev() to stop udev daemon.