A Portal URL is of the form
iscsi://[<username>[%<password>]@]<host>[:<port>]
and is used by command such as iscsi-ls during the discovery login phase.
During discovery we do not yet know the target iqn name, nor the lun of
any devices.
Add unidirectional chap support so we can authenticate to the target.
Make the login phase more "intelligent" so we can iterate over login
pdus until we have reached full feature phase
Add a new helper functions to parse a iscsi url and break it down
into elements in a structure
Update iscsi-inq to allow CHAP authentication
