Use the correct icon in the title bar

I just noticed the video window uses the wrong icon on Windows. It loads the 32x32 icon and scales it down instead of using the 16x16 icon:
![icon-before](https://f.cloud.github.com/assets/162837/2180086/ea4cbffa-96f6-11e3-89a0-c5c164b04ddd.png)

If `hIconSm` is left unset on the window class, Windows will choose the correct size from `hIcon`:
![icon-after](https://f.cloud.github.com/assets/162837/2180087/ee03c53a-96f6-11e3-949a-28ebff9cce76.png)

It's a pretty small detail, but it's easy enough to fix :)