Michael Goderbauer 54e3333182
Use bundled mingit on Windows if available (#14025)
In the packaged ZIP files for Flutter we bundle mingit on Windows to make setup for our users easier (they don't have to download and install git anymore). This change makes Flutter use the bundled mingit if it is available and if git is not installed on the system.

This change will still require that users add `flutter\bin` to their path or they'll have to execute `flutter\bin\flutter.bat` directly. A follow-up PR will add a pre-configured Flutter Console that people can start with a double-click to minimize setup even further.

Also in this PR:
* If 7Zip is not available to unpack the Dart SDK try 7Zip's standalone version.
2018-01-10 16:48:39 -08:00
..

Dart SDK dependency

The Dart SDK is downloaded from one of the supported channels, cached in bin/cache/dart-sdk and is used to run Flutter Dart code.

The file bin/internal/dart-sdk.version determines the version of Dart SDK that will be downloaded. Normally it points to the dev channel (for example, 1.24.0-dev.6.7), but it can also point to particular bleeding edge build of Dart (for example, hash/c0617d20158955d99d6447036237fe2639ba088c).