#19 Errors show error codes instead of messages

[Kimmo Varis]

When some operations fail (like loading a file) then error code is shown in message. Instead there should be error message. Users have no idea what those system error codes mean.

In file loading code:

char buf[500];
sprintf(buf, "Error code 0x%x occured while opening file %s.", errno, fname);
MessageBox(hwnd, buf, "Load error", MB_ICONERROR);