Fixing "juju help commands"

[Tim Penhey]

Hi folks,

More from the "let's fix the output" school of thought.

One thing that has bugged me about 'juju help commands' was the repeated 
mentions of "alias for <blah>".

I propose that we don't show aliases by default, and allow the user to 
task for them.

Also, the supercommand describe commands method was written before I 
knew about the tabular output, so some code could be cleaned up there.

Proposal:

juju help commands
   - shows the commands that are neither aliases, nor hidden
juju help commands --alias
   - shows either just the aliases, or everything including aliases
juju help commands --all
   - shows basic commands, aliases and hidden commands.

I'd like to add the ability to say a command is hidden so it doesn't 
show up in the commands list. The purpose for these could be debugging 
assisting type functions, like "dump-model" or "debug-controller" (two 
commands that don't yet exist).

Thoughts?

Tim