add NFS shared storage models and CLI.
change storage target driver class hieralchy.
add NFS target driver and make all them work.
update existing storage drivers.
add backup provider methods to raw file driver.
Fixed the version of dcell, celluloid, reel and http.
Fixed the mussel code as the interface for volume has changed.
Merge pull request #339 from axsh/fix-celluloid-version

Fix celluloid version
Merge branch 'master' into feature-nfs-volume
Merge pull request #338 from axsh/feature-nfs-volume

Add support for NFS shared storage.
Moved zeromq3 and zeromq3-devel from common to dcmgr
Merge pull request #340 from axsh/fix-dcmgr-package

Moved zeromq3 and zeromq3-devel from common to dcmgr
Merge branch 'master' into feature-indelibe-fs-v3

Conflicts:
	dcmgr/lib/dcmgr/configurations/sta.rb
	dcmgr/lib/dcmgr/drivers/iscsi_target.rb