Small patch for TfrxPictureView

Guillaume

This little patch enable Picturecache when FileLink is used.

In frxClass.pas

  TfrxPictureView = class(TfrxView)
  private
    FLastFile:string;
//....
  procedure TfrxPictureView.GetData;
//....
    if FileExists(s) then
      FPicture.LoadFromFile(s)
    else
      FPicture.Assign(nil);

    FPictureChanged:=(FLastFile='')or(FLastFile<>s);
    FLastFile:=s;
//....