* Bump target frameworks from netcoreapp1.0 to netcoreapp2.2.
Move global.json up to root of repo, change SDK ver to 2.2.100
Change .net core sdk in dockerfile for kokoro to ver 2.2.100
* Re-add curl install
* Change all exe target to 2.1
* Fix incorrect versions in global.json and Dockerfile
* Downgrade version to 2.1 to match exe targets
* introduce separate testing Dockerfile for C#
* revert changes to the shared Dockerfile
* use netcoreapp2.1 for C# conformance tests
* use language specific dockerfile for testing C#
* Edit compatibility tests script to use parameters instead of file copies
* install dotnet SDK on windows before running the tests
* update csharp_EXTRA_DIST
* Improve C# serialization performance of repeated fields for primitives.
* Changes based on feedback.
* Change compatibility tests to chec float, bool and double are fixed
* Changes based on feedback.
* In the compute methods use the newly created constants
* Increase C# default recursion limit to 100
This matches the Java and C++ defaults.
* Change compatibility tests to use execution-time default recursion limit
This way the same tests should pass against all versions, even
if the recursion limit changes. (The tests will be testing whether
different messages work, admittedly - but that's probably fine.)
Note that the compatibility tests have had to cahnge as well, to
cope with internal changes. (The test project has access to
internals in the main project.)
Fixes#3209.
This has one important packaging change: the netstandard version now
depends (implicitly) on netstandard1.6.1 rather than on individual
packages. This is the preferred style of dependency, and shouldn't
affect any users - see http://stackoverflow.com/questions/42946951
for details.
The tests are still NUnit, but NUnit doesn't support "dotnet test"
yet; the test project is now an executable using NUnitLite. (When
NUnit supports dotnet test, we can adapt to it.)
Note that the project will now only work in Visual Studio 2017 (and
Visual Studio Code, and from the command line with the .NET Core
1.0.0 SDK); Visual Studio 2015 does *not* support this project file
format.