[libvirt] C# PInvoke Library done, Nuget Package released

Libvirt C# Nuget package released at https://www.nuget.org/packages/Libvirt_Pinvoke/ This will add all necessary dll's and includes a full 1 to 1 mapping of the libvirt API 1.2.13 (http://libvirt.org/html/). All Structures, enums, delegates, and functions are included with the same naming and function.