[cli] set <var_boolean> <tab>?

[Andrew Cagney]

> I can either:
> 
>     o    Add a add_set_boolean_cmd() that is similar
>         to add_set_auto_boolean_cmd()
> 
>     o    Tweek add_set_cmd() to realise it is
>         a var_boolean and set things up accordingly.
> 
> If the latter, I should probably eliminate add_set_auto_boolean_cmd() and adding it to add_set_cmd().

Closer inspection reveals the rationale.  add_set_auto_boolean_cmd takes 
an explicit / strongly typed ``enum cmd_auto_boolean'' as the parameter 
that is updated.  add_set_cmd() takes a ``void *''.  I'll cook up a 
patch adding add_set_boolean_cmd().

Andrew