Updated VM script, RP for VM and updated HWs.

Updated the VM setup script for Ubuntu 12.04 with Ruby 1.9.3 and Rails 3.2.15. Added rottenpotatoes folder for vm setup. Added hw-skeletons folder with minor changes for Heroku issues, other warnings and Rails 3.2.15. Tested all CS 169.1x homework assignments with the VM and graders. Readme files included with details about changes, most of which are minor.