role: add ceph::role::base

This is the base class for configuring Ceph services by exclusively
using parameterless classes and global variables, as one would
with a simple ENC like Puppet Dashboard (although it is not limited
to working with Puppet Dashboard; any ENC will do).

Signed-off-by: Florian Haas <florian@hastexo.com>
role: add ceph::role::osd

Add class to configure a node as a Ceph OSD, inheriting from
ceph::role::base.

Signed-off-by: Florian Haas <florian@hastexo.com>
role: add ceph::role::mon

Add role to configure a Ceph MON with an ENC, inheriting from
ceph::role::base.

Signed-off-by: Florian Haas <florian@hastexo.com>
role: add example site.pp

Add an alternative version of the site.pp script, using roles.

Signed-off-by: Florian Haas <florian@hastexo.com>