Store patches meta info in patches configs (#470)

* 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.

Author: alexeykuzmin

.gitmodules

@@ -5,3 +5,7 @@
 	path = vendor/boto
 	url = https://github.com/piotrbulinski/boto.git
   ignore = untracked
+[submodule "vendor/pyyaml"]
+	path = vendor/pyyaml
+	url = https://github.com/yaml/pyyaml.git
+	ignore = dirty

patches-mas/.patches.yaml

@@ -0,0 +1,10 @@
+repo: src
+patches:
+-
+  owners: zcbenz
+  file: 001-blink_no_private_api.patch
+  descripion: null
+-
+  owners: zcbenz
+  file: 002-no_private_api.patch
+  descripion: null

patches-mips64el/.patches.yaml

@@ -0,0 +1,38 @@
+repo: src
+patches:
+-
+  owners: null
+  file: 005-Add-support-for-using-seccomp_bpf-on-mips64el.patch
+  descripion: null
+-
+  owners: null
+  file: 006-Set-kernal-page-size-to-16K-on-loongson-MIPS-archtec.patch
+  descripion: null
+-
+  owners: null
+  file: 007-Add-mips64el-redhat-linux-to-gcc_toolchain-for-mips6.patch
+  descripion: null
+-
+  owners: null
+  file: 009-Fix-mips-cross-toolchain-build-src-crypto-ec-p256-64.patch
+  descripion: null
+-
+  owners: null
+  file: 010-Fix-error-about-relocation-truncated-to-fit-R_MIPS_C.patch
+  descripion: null
+-
+  owners: zcbenz
+  file: 011-backport-sqlite-8a87f7e.patch
+  descripion: null
+-
+  owners: zcbenz
+  file: 012-backport-sqlite-9851f2e.patch
+  descripion: null
+-
+  owners: zcbenz
+  file: 013-backport-sqlite-3d8ec48.patch
+  descripion: null
+-
+  owners: zcbenz
+  file: 014-support-old-nss.patch
+  descripion: null

patches-mips64el/third_party/ffmpeg/.patches.yaml

@@ -0,0 +1,6 @@
+repo: src/third_party/ffmpeg
+patches:
+-
+  owners: zcbenz
+  file: 002-Fix-build_ffmpeg-with-cross-prefix-mips64el-redhat-l.patch
+  descripion: null

patches-mips64el/v8/.patches.yaml

@@ -0,0 +1,6 @@
+repo: src/v8
+patches:
+-
+  owners: zcbenz
+  file: 002-Fix-v8-loongson-page-size.patch
+  descripion: null