Shots now know their absolute error distance.
Distinguish between sighter and match shots.
Remove references to cards.
Break up the Megalink data source a little.
Make the specs catch up with the code.
Add Target#calibre and Megalink#distance
Series == 1 is sighters, anything else is match shots.
Deal better with time underflow.
Move the Megalink fixture helper into its own file
Start work on decoding the SCATT files.