Added optional currency conversion for goals: count purchases in other currencies using fixed exchange rates or daily European Central Bank reference rates.
Added a per-goal list of additional currencies that contribute to the goal.
Refunds of converted purchases are now deducted at the rate of the original purchase.
Fixed completed goals displaying progress with a newly edited currency or target.
Fixed goal progress rebuilds that could stay queued indefinitely after a manual purchase ledger rebuild was interrupted.
Fixed queued goal progress rebuilds waiting on each other instead of running.