auto completion with tab: separate commands and tree structure

[Reed Wade]

Hello,

I didn't worked on the pass bash autocomplete script but I think this is
a bash completion limit and not a pass one.

The autocompletion script only put all available words and bash order them
alphabetically.

I'm not sure it is only possible to force an order. I guess this could
be "anti-normal" in regards of other autocompletions order.