Change FileWriterPlugin validation to expect initial frame 0
Change FileWriterPlugin validation to expect initial frame 0

Also check if frame expected based on offset, not number
This means an offsetAdjustment of 1 can be given to allow
it to work for Percival and Excalibur.

odin-detector/odin-data,percival-detector/odin-data,percival-detector/odin-data,odin-detector/odin-data,percival-detector/odin-data,percival-detector/odin-data,odin-detector/odin-data,odin-detector/odin-data,percival-detector/odin-data,percival-detector/odin-data,odin-detector/odin-data,percival-detector/odin-data,odin-detector/odin-data,odin-detector/odin-data