Instead of making the change just for ansible-provision.sh make the
change for all ansible runs.  Most of them don't currently have this
problem right now but I think it makes sense to make them all consistent
and not have to worry about this problem in the future.

Counterpart to the Vagrantfile for testing individual Ansible roles.

This modifies the edx_ansible role to dump a clean var
file on disk that can be used for subsequent update runs
so that config vars will not be lost

also changes the ansible tmp directory to /var/tmp which is a better
location than using $HOME (used for debugging mostly)

* Created new directory structure outlined in the README
* Created the LMS role which for now just creates teh application config
files
* Created the common role
* Updated the cf playbook to accept arguments