Culture cow installs itself properly on internal-webserver setup and auto-restarts on crash.

Test Plan:
Apply this diff to live internal-webserver's aws-config repo, cuz hey, why not
Comment out all install_* lines at bottom of internal-webserver/setup.sh except for install_root_config_files and install_culture_cow
Run internal-webserver/setup.sh and verify that culture-cow gets installed properly, starts running, and shows up in our hipchat instance.

Reviewers: csilvers

Reviewed By: csilvers

Differential Revision: http://phabricator.khanacademy.org/D10670