Build problems on windows

Hi,

Here is a little fix to Build on a Windows environnement.

It's essentially some copy-paste errors on your lasts commits.

The only one I'm not confiant with, is the 0*8000000 => 0x8000000 change in SparkleSetupWindow.cs.
Because it's obviously working on your environnement.

As it seems to be an encoding problem, please try with my 'x' to see if your compiler accept it.

Regards,
Gerard.

ps : By the way, thanks for this awesome tool !