* Add PyYAML submodule
https://github.com/yaml/pyyaml
* Install PyYAML on bootstrap
* Ignore dirty state of the pyyaml submodule
It creates a "build" directory under its root when built.
* Use argparse in the apply-patches script
And provide a target arch as a named argument.
* Store patches meta info in patches configs
Use a patches config to defines order of patches,
specify a patch owner, and provide a description for a patch.
It should help us to avoid order collisions, make merge conflicts explicit,
and help find owners since git blame might not be reliable
because of frequent changes during Chromium upgrades.
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