Version 3.24.35.27

Merged r19606, r19620, r19707 into 3.24 branch.

Update test262 to get test data from github

Update README about where the test262 files are downloaded from.

Update .gitignore to new test262 package name.

BUG=
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/223673004

git-svn-id: https://v8.googlecode.com/svn/branches/3.24@20470 ce2b1a6d-e550-0410-aec6-3dcde31c8c00