* Project file refactor
Move all the .csproj files to the new .NET Core style.
This doesn't make any difference for compiling for Framework,
but it does reduce a ton of useless boilerplate.
As an extension of this, killed a bunch of uncompiled & unmaintained .cs files.
Compiling for release (to profile) works now.
Removed AnyCPU targets from the solution file.
* Fix compiler warnings.