We've changed bm_disk_entry.DiskEntry.Save to add a new parameter: "stealth".
- by default, stealth = False
- if stealth = True when saving:
- no monitors are notified of changes
- the mtime and atime of the "index.pyd" files are preserved
- timestamps are not updated
- the purpose is to allow writing scratch-pad or administrive information without triggering unnecessary workflow. For example:
- when recording that "ping" was sent
- when recording that an email was sent
- to support pings, we've added two more functions to DiskEntry
- SetPing(ping_service, data)
- GetPing(ping_service)

