Volume driver for the eguan replicated storage backend

This blueprint outlines porting the cinder volume driver for the eguan
replicated storage backend (http://github.com/oodrive/eguan) to kilo.

Eguan is a replicated storage system written in Java and C/C++.

It was implemented by Oodrive (http://www.oodrive.com) as a storage prototype
for the nu@ge project (http://nuage-france.fr/).

Eguan provides storage volumes to clients via an iSCSI or NBD connection and
manages the history of its volumes. Each volume is made available as devices and
snapshots, replicated on several nodes.

The system uses a copy-on-write strategy for the snapshots and data
deduplication to improve storage utilization.

The current driver was developed for icehouse and can be obtained from
Github: https://github.com/oodrive/cinder/tree/eguan-driver