This makes the code shorter, simpler and more consistent, and also
ensures that the (same) debug messages are always emitted and the
packet.payload field is consistently set to NULL always, etc.
As we're downsampling, several record time stamps can match the specified
trigger time. For this reason, it's possible that several trigger packets
are sent when a file is loaded. This prevents the issue and sends a
trigger packet only on the first matching record.
Soeren Apel
Uwe Hermann