Enable support for use of Erasure Coded (EC) pools for
nova disks when RBD is used to back ephemeral storage volumes.
Add the standard set of EC based configuration options to the
charm.
Update Ceph broker request to create a replicated pool, an erasure
coding profile and an erasure coded pool (using the profile) when
pool-type == erasure-coded is specified.
Resync charm-helpers to pick changes to the standard ceph.conf
template and associated contexts for rbd default data pool mangle
due to lack for explicit support in OpenStack Services.
Update context to use metadata pool name in nova configuration
when erasure-coding is enabled.
Change-Id: Ida0b9c889ddf9fcc0847a9cee01b3206239d9318
Depends-On: Iec4de19f7b39f0b08158d96c5cc1561b40aefa10
5f4f95ef13