=head2 silly_bool( $value )
-Returns 0 if the value starts with y, Y, t or T.
-Returns 1 if the value starts with n, N, f or F.
+Returns 1 if the value starts with y, Y, t or T.
+Returns 0 if the value starts with n, N, f or F.
Otherwise returns the value itself.
Use this for handling boolean content like tax_exempt.