Make sure to apply os.path.expanduser to config keys

That is, make sure to apply it to user-supplied paths
as well as default paths.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Small cleanups relating to the sshprivkey parameter.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Move to placing Ubuntu repos into sources.list.d

add-apt-repository writes to /etc/apt/sources.list only unless the repo is a PPA. This can cause problems when using something like cloud-init, that by default clobbers the file with it's own template.

It is also better practice to use the sources.list.d approach to add in more repos instead of appending to sources.list

Add TDL documentation and update RNG
Fix a udev / grub problem
See https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/604335
      https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/565146
      http://lists.opensuse.org/opensuse-bugs/2012-04/msg00301.html