Allow delete to work with "lunX" as param

Handle invalid LUNs cleanly.

Signed-off-by: Andy Grover <agrover@redhat.com>

Merged by Jerome Martin <tramjoe.merin@gmail.com>
Conflicts:
	targetcli/ui_target.py
Remove "Successfully" from ui_target info messages

Not needed, and now matches ui_backstore.py usage.

Merged by Jerome Martin <tramjoe.merin@gmail.com>
Conflicts:
	targetcli/ui_target.py
Fix TPG summary to be red if disabled

Almost all the time if a TPG is defined, we want it enabled. Make sure
it's visually obvious to the user if a TPG has somehow become disabled.

Signed-off-by: Andy Grover <agrover@redhat.com>
Call _check_self() in UIRTSLibNode.execute_command()

The object may load its driver in response to check_self(), and will
throw an exception if things go wrong.

Signed-off-by: Andy Grover <agrover@redhat.com>
Update manpage

Add sections on settings groups

General rewriting and clarifications.

Signed-off-by: Andy Grover <agrover@redhat.com>

Merged by Jerome Martin <tramjoe.merin@gmail.com>
Conflicts:
	targetcli.8
Make TPGs called tpgX in ui instead of tpgtX

Update manpage accordingly.

Signed-off-by: Andy Grover <agrover@redhat.com>
Finished renaming tpgt to tpg

* Previous patch by Andy changed the name in the objects tree.
* Now updated messages and doc too.