Add autoload magic comments for the functions exposed by google-c-style.

This should make packaged versions of google-c-style (like from MELPA)
provide the symbols without doing explicit 'require.

Patch by Kimmo Kinnunen <kkinnunen@nvidia.com>.

git-svn-id: http://google-styleguide.googlecode.com/svn@139 955884f1-7149-0410-9467-59e7ac3f4d80