Add fully automated mode to push-to-trunk script.

Now there are three modes to run the script:
(1) default: semi-automated
(2) manual (-m option), like in the old script
(3) forced (-f option), no user input required no editor check

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/102253002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18247 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Revert "Implement hyperbolic math functions for ES6."

BUG=

Review URL: https://codereview.chromium.org/104003002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18248 ce2b1a6d-e550-0410-aec6-3dcde31c8c00