Systemd overrides have been added to the service unit files for all
beats and services. All of the playbooks have been updated to make them
look and feel uniform.
This also sets handlers within the playbooks so that we're improving the
idempotence.
Change-Id: I2dd3183dae4bfddc607cc74f9dfb7af115b80abc
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>