Lock file cleaner

Sometimes, the lock file does not disappear altough the correspoding sedot process has been finished. We have to confirm that the sedot process is not there anymore before removing this lock file. Therefore, we have to find a way to monitor/check the process.

The easy way to do that is by saving the PID of sedot process to a file, such as log/pid/debian.pid. This entry should be cross-checked with the actual running process and also the LOCK file under target directory. If the LOCK file exists but the process doesn't, then we can remove the LOCK file safely.