dxdiag: add basic command line parsing

[Henri Verbeet]

2009/8/26 Austin English <austinenglish at gmail.com>:
> Based on Dan Kegel's patch he wrote for Louis Lenders old implementation.
>
It probably doesn't make much of a difference for command line
parsing, but I think you want to make dxdiag explicitly unicode from
the start (new programs in general, really). It also seems to me that
this patch doesn't do a whole lot in practice.