buildserver: move apt setup to a shell script

This makes it so there is only a single `apt-get install` command run,
instead of one command per-package like with the chef script.  It also adds
`apt-get upgrade` to make sure that the base box is fully up-to-date.

buildserver/cookbooks/kivy/recipes/default.rb

@@ -1,6 +1,4 @@
 
-user = node[:settings][:user]
-
 %w{cython python-pygame python-pip python-virtualenv python-opengl python-gst0.10 python-enchant libgl1-mesa-dev libgles2-mesa-dev}.each do |pkg|
   package pkg do
     action :install