Moving locale code from i18n-extension.cc. Each part of the API now has separate cc file, and only extension related code is left in i18n-extension.{cc,h}.
There are no functional changes in this CL.
Review URL: http://codereview.chromium.org/6840024

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7608 ce2b1a6d-e550-0410-aec6-3dcde31c8c00