Kas

- kas: add "checkout" and for-all-repos subcommands
- kas: add python 3.9 compatibility
- kas: improve documentation
- config: add build_system property to pre-select OE/Yocto or Isar
- kas-container: rename from kas-docker
- kas-container: add support for build_system property (making --isar optional)
- kas-container: adjust environment variables interface
- kas-container: switch to github container repository
- kas-container: add support for Debian bullseye cross building
- kas-container: add zstd package

- kas: allow extra bitbake arguments to be passed
- kas: add --force-checkout and --update arguments to ease CI usage
- kas: allow for layer-free repositories
- kas: fix cloning of repos without default branch
- kas: enable standard-conforming .yaml file extensions
- kas-docker: enhance with podman support
- kas-docker: switch to /bin/bash as SHELL per default
- config: Allow a default refspec to be specified
- config: Allow a default repo to be specified for patches

- repos: Silence pycodestyle error (that broke docker image generation)

- Add support for S3 fetcher to docker image
- Lift Python minimal requirements to 3.5
- Fix reporting of of repo patch IDs
- config: use 'qemux86-64' instead of 'qemu' as default for KAS_MACHINE
- Ensure SSH key ends with newline
- kas-docker: Make it harder to run as root
- kas-docker: Make loop device passing optional
- kas-docker: Various fixes

- Add support for Yocto 3.0 / latest Isar
- Move docker image to Debian buster
- Add git-lfs support to docker image
- Add Yocto testimage dependencies to docker image

- Restore mercurial support
- Add -c and --cmd as aliases for --task
- Fix repo patching when using a branch name as refspec
- Update repo remote URL on kas file changes
- kas-docker: fix SHELL forwarding
- kas-docker: use released image, rather than "latest"
- kas-docker: allow to define custom image version
- kasproject/kas: enable devshell and menuconfig targets
- kasproject/kas image: add gnupg and quilt
- kasproject/kas-isar image: fix /var/tmp handling