Lock file reporting

[Fajran Iman Rusadi]

The report page can check whether a lock file exists or not. Currently, it only checks for .SYNC-in-Progress-* which looks sufficient but doesn't. If the mirror mirrors from an upstream mirror that also uses sedot, it may find .SYNC-in-Progress of the upstream.

Therefore, looking for files prefixed with .SYNC-in-Progress is not correct way to check lock file existance. The reporting script should find for specific lock file, that is, the complete file name with hostname in it.

In order to deal with multiple downloader machines, the list of hostnames can be written somewhere under etc/ directory, such as etc/report.nodes. Then, package and node informations are used to determine the specific lock file.