Remove bunch of stuff from contrib/ hierarchy.
* ps/contrib-sweep:
contrib: remove some scripts in "stats" directory
contrib: remove "git-new-workdir"
contrib: remove "emacs" directory
contrib: remove "git-resurrect.sh"
contrib: remove "persistent-https" remote helper
contrib: remove "mw-to-git"
contrib: remove "hooks" directory
contrib: remove "thunderbird-patch-inline"
contrib: remove remote-helper stubs
contrib: remove "examples" directory
contrib: remove "remotes2config.sh"