+17Jun20=======================================================================
+1. Change the Spot file reading mechanism back to the default of using 'tac'.
+08Jun20=======================================================================
+1. Fix show/mydx (lack of) filtering bug.
+2. Add qra locator to prefix_data.pl.
+3. Add 4 digit qra square for spotted callsign if show/dxgrid is enabled.
+4. Fix general filtering bug where erroneous input causes crashing.