This is a branch cleaning up old `#if` clauses, `.csproj` bits, Linux build compatibility, and a few other tid-bits (broken out by commit).
In general: we're on 3.0 tooling and all previous cruft has been removed.
Due to the way VS test works (by injecting an executable entry point), the performance tests needed to be factored out. I also organized all of our existing tests better along the way.
Actual code changes to Dapper itself are very minor, only formatting and documentation fixes (which we need many more of).
The build.ps1 script is upated to work, but note that <frameworkAssemblies> is not working in .nuspec inside the packages in the new .csproj system. I consider this to be a blocker. Issue is here: https://github.com/NuGet/Home/issues/4853
Nick Craver