scripts/convert-srcuri: Backport SRC_URI conversion script from master branch
This script handles two emerging issues:
1. There is uncertainty about the default branch name in git going forward.
To try and cover the different possible outcomes, add branch names to all
git:// and gitsm:// SRC_URI entries.
2. Github are dropping support for git:// protocol fetching, so remap github
urls as needed. For more details see:
