Some improvements to make it more .NET friendly

The "list" of what I have done and what I'm going to do is here:

- [x] Change the submodule to use public repository URL
- [x] Update the wrapper to the latest snowcrash version
- [x] Change configuration for Release version of DLL (it does not compile, actually)
- [x] Make it compile on AppVeyorn  [![Build status](https://ci.appveyor.com/api/projects/status/3d0a3hebo6u2jo1w)](https://ci.appveyor.com/project/XVincentX/snowcrash-dot-net-wrapper)
- [x] Create a [nuget package](https://www.nuget.org/packages/Snowcrash.NET/) and autopush on it (**x86** only for now)
 [x] Run a code analisys on the entire project (removed disposable warnings)