Inactive player purge & reboot speedup

[idles]

Some 8200 inactive players were purged, the criteria used to purge
- Inactive for more than 2 years, less than 100k exp or
- Inactive for more than 1 year, less than 10k exp.

Also the reboot (read: backup) process was somewhat optimized, the game should be back up in less than 10 minutes after a reboot. Further optimizations are possible, but troublesome to implement.