* Adding GTK extension methods
* Add initial implementation for Xamarin.Forms GTK
* Better exceptions
* GTK v2 does not build on Windows CI
This is because of mono not being installed. I could install it, but typically
this is not available on normal dev boxes. So, to make things easier, just
build on mac and linux.
* Upgraded a good few things
- multitargeting for netstandard1.3, netstandard2.0, netcoreapp3.0 and net45
- iOS, tvOS, macOS, watchOS now builds on non-macOS (not embedded binaries)
- removed empty assembly infos
- using Directory.Build.* to clean up a few things
- improved the msbuild tasks to properly skip
* Add the targets file to the nuget
* Let all the tests run before failing the build
* Pack and validate in one go
* Update the samples to use the new projects
* Use VS 2017 for native builds for now
* Update Dockerfiles
* removed references from Views.WPF to OpenTK #1029 (#1078)
* Install the type redirector
* Update depot_tools
* Don't do any signing for macOS
Co-authored-by: Tyson Williams <34664007+bender2k14@users.noreply.github.com>
