Add .vimrc file to vagrant and solve the 2 most annoying things about vim

Per brandwaffle's request, I've added a .vimrc file to the provisioning, identical to the way the .bashrc file is handled.  The .vimrc file allows you to save files using :WQ as well as :wq (makes it case insensitive) and will automatically do sudo if you are editing a root file as a regular user without having to exit vim and first do sudo - it will just do sudo upon save.