Comment clean up.

[dlemstra]

When going through the code I noticed that at various places there are comments like this:

// If control data pointer is NULL return NULL.
if (control_data == NULL)
{
    return NULL;
}

This is stating the obvious and I am wondering if the team would mind me going through the code to remove them? I don't think they add value and some of them are even incorrect:

// If control data pointer is NULL return DFALSE
if (control_data == NULL)
{
    return NULL;
}

[hakonlarsson]

You're quite right, it doesn't make sense to me either. Please do go ahead and remove them.

[petterreinholdtsen]

This issue should have been closed when #10 was merged.