Handlify escape and unescape.

R=mvstanton@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/12326015

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13702 ce2b1a6d-e550-0410-aec6-3dcde31c8c00