iSCSI: remove recovery from transport-layer connection failure(?)

[csapuntz@csapuntz-u1.cisco.com]

Currently, iSCSI is spec'ed to recover from transport-layer
connection failures.

The main motivation for this decision was to support tape backup
applications that are quite sensitive to any failures that get
propogated to their layer.

However, there are other ways of doing backup over IP than
SCSI/iSCSI.  NDMP (www.ndmp.org) and devices that implement it are
already shipping.

So, perhaps we can remove the requirement of recovering from
transport-layer connection failures in iSCSI. This would simplify
the protocol somewhat.

Thoughts?

-Costa