atmlib: add stub dll

[Nikolay Sivov]

Austin English wrote:
> Needed by photoshop cs4. See bug 16385.
>   
> diff --git a/dlls/atmlib/atmlib_main.c b/dlls/atmlib/atmlib_main.c
> new file mode 100644
> index 0000000..bb17989
> --- /dev/null
> +++ b/dlls/atmlib/atmlib_main.c
> @@ -0,0 +1,45 @@
> +/*
> + * MSSIGN32 implementation
> + *
> + * Copyright 2009 Austin English
> + *
>   

Hi, Austin, not mssign32 ).