262 modify the reply or not algorithm (F6FVY) (#263)

#262 Modify the "reply or not" algorithm (F6FVY)
    
The "reply or not" algorithm has been modified to allow callers with
long callsigns to reply, even if only few letters are caught.
This change integrates this change from 2018 into MRCE mainline.

DxOper.pas

@@ -148,12 +148,14 @@ procedure TDxOperator.SetState(AState: TOperatorState);
 
 function TDxOperator.IsMyCall: TCallCheckResult;
 const
-  W_X = 2; W_Y = 2; W_D = 2;
+  W_X = 1; W_Y = 1; W_D = 1;
 var
   C, C0: string;
   M: array of array of integer;
   x, y: integer;
   T, L, D: integer;
+
+  P: integer;
 begin
   C0 := Call;
   C := Tst.Me.HisCall;
@@ -187,13 +189,15 @@ function TDxOperator.IsMyCall: TCallCheckResult;
       M[x,y] := MinIntValue([T,D,L]);
     end;
 
-  //classify by penalty
-  case M[High(M), High(M[0])] of
-    0:   Result := mcYes;
-    1,2: Result := mcAlmost;             
-    else Result := mcNo;
-  end;
+  P := M[High(M), High(M[0])];
 
+  if (P = 0) then
+    Result := mcYes
+  else if (((Length(C0) <= 4) and (Length(C0) - P >= 3)) or
+       ((Length(C0) > 4) and (Length(C0) - P >= 4))) then
+    Result := mcAlmost
+  else
+    Result := mcNo;
 
   //callsign-specific corrections