Import aom library

This is the reference implementation for the Alliance for Open Media's av1 video code.

The commit used was 4d668d7feb1f8abd809d1bca0418570a7f142a36.

third_party/aom/tools/author_first_release.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+##
+## List the release each author first contributed to.
+##
+## Usage: author_first_release.sh [TAGS]
+##
+## If the TAGS arguments are unspecified, all tags reported by `git tag`
+## will be considered.
+##
+tags=${@:-$(git tag)}
+for tag in $tags; do
+  git shortlog -n -e -s $tag |
+      cut -f2- |
+      awk "{print \"${tag#v}\t\"\$0}"
+done | sort -k2  | uniq -f2