Updates:
- /stats Show descriptive statistics.
- /interval [low] [up] List players' balance in a specific interval.
- /perc [low] [up] Show the percentile of players' balance.
- /checkrecords Show all operations.
- /checkrecord <operation_id> Show details of a specific operation.
- /restore <operation_id> Restore a specific operation.
- added language option in config
- added sqlite for records
- fixed some bugs
- some potential new bugs