Add C# library and tests into a .NET project/solution

[mattkoch614]

• Added a solution file to contain the C# library & associated tests
• Added a .NET Standard 2.0 class library project to house the main library file
• Added a Console Application project to house the tests
• Added both projects to the solution file
• Added some basic metadata for the C# library in order to easily create a Nuget package
• No physical file locations were modified

[mattkoch614]

@NeilFraser Any thoughts on this PR?

[mattkoch614]

Bump (is that still a thing in 2018?)

[koliyo]

Thanks for PR. Hope someone will take a look at this.

[mattkoch614]

Me too!

[John0King]

does this actully compatable with .netstandard ? the code using System.Web which it only work with .net framework! it should be replace with System.Net.WebUtility instead of the old System.Web.HttpUtility