06: Build nuget package

.. developing ...

see

https://github.com/prepare/Espresso/tree/master/espr_build_nuget

https://github.com/prepare/Espresso/blob/master/espr_build_nuget/Program.cs

key note:

1. How to pack native dll (lipespr.dll) into nuget.

2. DllImport not found? , nuget not copy native dll to proper folder? or nuget not load proper dll?

3. take care of runtime, platform id

questions:

  when package id is the same as managed assembly, 
  the bundled native dlls are not loaded,
  but when the package id name is different, it works!,
  2 days pass .... :'( 
  but now it was resolved :)   

see more

1. https://blog.3d-logic.com/2015/11/10/using-native-libraries-in-asp-net-5/

2. https://docs.microsoft.com/en-us/dotnet/articles/core/tools/project-json#frameworks

3. https://docs.nuget.org/consume/projectjson-intro