Revert "Add .dir-locals.el."

After some discussions, this seems to be the wrong approach. We should probably
either link to the Google style guide and its related configuration files, or
even add a Makefile target for downloading it.

Furthermore, with this change Emacs keeps popping up an annoying confirmation
window for new files.

Review URL: https://codereview.chromium.org/12432013

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13889 ce2b1a6d-e550-0410-aec6-3dcde31c8c00