Add CSharpAnalytics Library

This pull request includes the CSharpAnalytics library from https://github.com/AttackPattern/CSharpAnalytics

In includes the original source code, and the version that I have modified to allow it to work on .NET 4.0 both in terms of the language changes (no async/await) and a few limitations in the .NET networking libraries.

The code is licensed under Apache 2.0 as per: https://github.com/AttackPattern/CSharpAnalytics/blob/master/Source/LICENCE.txt

@ikeough PTAL