Renamed all config vars, split roles into separate file

Role config vars in roles/*/vars/main.yml are now `role_name__var`,
and can be overridden by setting them in config.yml.

Roles are now stored in a separate file from the rest of the config to
make it easier to auto-generate a list of roles to include based on the
contents of the roles/ dir, though this has not yet been implemented.
Merge pull request #1 from usernamenumber/config_formatting

Renamed all config vars, split roles into separate file
trivial typo fix
Add instructions for adding new modules
Update README.md
Disable building ISO by default

Enable by overriding `build_iso__enabled` in `ansible/config.yml`. See the root `README.md` for details.
Added apt_basic__upgrade_packages

Controls whether or not apt-get upgrade is run during provisioning
make desktop role start GUI
Fix for issue #2: kalite fails at startup

Problem appears to be that an old (and incomplete) copy of the kalite
sqlite database was accidentally checked into git.-

This set of changes does the following:

* Remove the old database and another .pid file that shouldn't be there
* Add both to a new .gitignore for the role
* Add a playbook entry to ensure installation of the sqlite client
  * not really necessary, but it doesn't hurt to have it, and it may make troubleshooting easier in the future.
Make kalite only restart if something changes
Merge pull request #3 from usernamenumber/kalite-add_sqlite

Fix for issue #2: kalite fails at startup
Merge pull request #7 from usernamenumber/start_gui

Fix for #4: make desktop role start GUI
Merge pull request #8 from usernamenumber/optional_package_update

Added apt_basic__upgrade_packages
Added new handler to restart apache
It looks right like this