This adds our self-compiled copy of the MinGit executable (built from the flutter/git repo) to the archive when building an archive for Windows.
I also tweaked the internal API for prepare_package.dart so that there's a single entry point to build an archive.
* fix updrade script; upgrade to the latest package versions
* exclude special dependencies from transitive closure
* fix stack trace handling in flutter_test due to stack_trace change
* change type on _emptyStackTrace
* Pin all dependencies ONCE AND FOR ALL
This replaces the secret `flutter update-packages --upgrade` with a destructive `flutter update-packages --force-upgrade` that actually goes and pins every dependency and transitive dependency in every flutter package to the same version.
* Add comments.
Adds an initial integration test that:
1. captures laid-out widget size
2. focuses a text field to show the keyboard and resize the view
3. unfocuses the text field to dismiss the keyboard and resize the view
4. verify that the final widget size matches the initial size