* bin/mudur.py: The I/O redirection of start-stop-daemon
	doesn't work at all. Implemented a new method run_async()
	which runs a command in background and optionally redirects
	its output and error streams.
	* bin/mudur.py (startUdev): Use run_async() for spawning
	udevadm monitor instead of buggy start-stop-daemon.

* 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.

	* bin/mudur.py (setupUdev):
	Use start-stop-daemon for udev startup,
	The default timeout is 180, no need to give it as a parameter,
	Call "udevadm monitor" for logging into /dev/.udev.log,
	Call /usr/bin/udevsync after rw remounting of the root filesystem
	for copying the log file and the persistent network/cdrom rules
	from /dev into /var/log and /etc (#8458, #8520).

BUG:FIXED:8458
BUG:FIXED:8520