LVM: update iscsi target on volume attach

This patch updates the existing iSCSI target for a LVM volume during
attach.  This is necessary in the event that a user extended the volume
after creation so that the correct size is visible to the host.

This adds support only for tgtadm.  Other changes may be needed for
ietadm/lioadm to provide the same functionality.

Change-Id: I185a90ffc4d50dd9f91381df07289476fa792043
Closes-Bug: #1248415
Remove legacy config option 'connection_type'

'connection_type' is a legacy config option originated from Nova.
Nova used this option to specify underlying virtualization type for
compute service and had deprecated it (with 'compute_driver') in
Folsom and had it removed in later release.  In Cinder Folsom release,
the XenSMDriver in Cinder used this config option to verify the target
hypervisor but in Grizzly XenSMDriver has been renamed and refactored
and no longer used this config.  Therefore, this option is dead for
a long time, and should be removed.

Change-Id: I4d72f31302fa813df42e71224151148a9c4a76c7
GlusterFS: Synchronize additional operations

create_cloned_volume() and copy_volume_to_image() should also be
locked against other driver operations to prevent collisions
from concurrent updates of snapshot metadata or volume file data.

Closes-Bug: #1267983

Change-Id: Idd6158bfbe4dc049c33fa58b40d3d570fc244d01
Use a *args pass-in instead of a list one

Change-Id: Ieef972f413dcf444d26c15a02d1993acf7cbb079
Fix os.getlogin() problem with no tty

Catch OSError(s) from  os.getlogin() and fall back to looking at
environment variables to figure out the user's name. The OSError
is thrown where there is no tty for the python process when
os.getlogin() is called.

Related-Bug: #1221491

Change-Id: I2bd735c9669ba9d25da108da44ea602f358b2dcc
Register EMC config options globally

The registration allows the oslo sample config generator
to detect the config options and extract automatically
a config template.

Change-Id: Ib181d734dddbd9b6a664439286969b832d6536e7
Fix exception log msg in attach volume method

Attach volume happened when volume's status is attaching or available, but
the exception msg only contain info about "available". So fix it.

Change-Id: I1caf83b94b3e4158eff88871a4187041a25e5d1c
Closes-Bug: #1270020
Merge "LVM: update iscsi target on volume attach"
Merge "Use a *args pass-in instead of a list one"
Merge "Remove legacy config option 'connection_type'"
Merge "GlusterFS: Synchronize additional operations"
Merge "Fix os.getlogin() problem with no tty"
Merge "Fix exception log msg in attach volume method"
Merge "Register EMC config options globally"