change box_url to be the same as controller
change box name to deis-controller for consistency
s/controller/server/g for consistency

this is a base deis box. Since it applies to both controllers and
nodes, there's no need to name the vagrant box one or the other.
This allows users to download the box once and never have to
download it again.
change default box_url. Fixes #581
Merge pull request #582 from opdemand/change-vagrantfile-template-url

change box_url to be the same as controller
Updated EC2 AMIs from prep scripts.
Updated Chef references to 11.8.2.
Merge pull request #584 from opdemand/chef-up

Updated Chef references to 11.8.2.
Merge pull request #583 from opdemand/new-amis

Updated EC2 AMIs from prep scripts.
fix buff-extensions downgrading
Merge pull request #585 from opdemand/fix-buff-extensions

fix buff-extensions downgrading
Updated submodule SHAs.
update DO readme to match correct script name
be a little more explicit with the creation of snapshots
Merge pull request #588 from davidcollom/patch-1

update DO readme to match correct script name
pin knife-rackspace to 0.9.0 or higher

we require --ssh-keypair to be available, which was introduced in
[v0.9.0](https://github.com/opscode/knife-rackspace/blob/master/CHANGELOG.md#v090).
Updated deis-cookbook SHA to match master.
Fixed a typo in vagrant provisioning script.
Use sudo to create symlink to dsh. #596
added install script for avahi