[Feature] Multiplatform Support through Mono Runtime

[Ruedii]

I notice this is written in Visual Basic.

It should not be too much work to port this to the Mono Runtime from the .Net runtime.
This would allow a multi-platform .exe file that can run on either .Net or Mono. (Almost all programs that run on Mono run on .Net but it isn't always the other way around.)

This would allow support of all platforms that SteamCMD supports (currently Win32/Win64, MacOS X, Linux32, Linux32/Linux64-MultiLib)