* Add codegen test for namespaced unions
* [Rust] Handle cross-namespace union use
* [Rust] Test namespace handling
* [Rust] Drop trailing whitespace in codegen
* [Rust] Set flags in generate_code.bat to match .sh
* [C#] Add additional namespace test file
* ENABLE_SPAN_T doesn't require UNSAFE_BYTEBUFFER.
Change to ENABLE_SPAN_T that doesn't require UNSAFE_BYTEBUFFER.
* Selectable framework.
Changed target framework to allow selection of 2.0 or 2.1 (or higher)
* Added target framework version check.
* Add core test project.
* Added run on .Net Core.
