* 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.
Any *.patch files added to the (not-yet-extant) patches/ directory will
be applied before we build.
If patches fail to apply, we'll revert all changes and try again.
Reverting will delete our copied gyp files, so we have to make sure to
copy them *after* applying patches.
Alexey Kuzmin
Cheng Zhao
Aleksei Kuzmin
Kevin Sawicki
Adam Roben