This is a major overhaul of the build, projects and infrastructure, but, not to any actual code.
- Using multi-targeting for:
- PCL (backwards compatibility for the time being)
- .NET Standard 1.3
- .NET Standard 2.0
- No more .nuspec files, the .csproj does this with the `Pack` target
- No more AssemblyInfo.cs files, the .csproj has all this info
- No longer the build system, but rather a single solution for each library with the code, tests and samples
- No more shared projects
- Using Xunit instead on NUnit as this has better cross-platform support
- A single PowerShell script will build the entire repository