george/prediction_tracker: Manage and score predictions on arbitrary topics. @ 0bebb34d9541d222065ccd6a1ac928b23e5720c0

George C. Privon 0bebb34d95 add listing of completed tasks		%!s(int64=6) %!d(string=hai) anos
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create_database.rkt	3b8fae716c don't force entry of prediction text every time, since prediction has unique ID	%!s(int64=6) %!d(string=hai) anos
scoring_rules.rkt	c7a036e748 math library not needed for expt/log	%!s(int64=6) %!d(string=hai) anos
update_predictions.rkt	0bebb34d95 add listing of completed tasks	%!s(int64=6) %!d(string=hai) anos