[MERGE] Make command discovery entirely callback driven.

[Ian Clatworthy]

Robert Collins wrote:
> On Mon, 2009-06-15 at 17:03 +1000, Ian Clatworthy wrote:
>>
>>>>>>> +def get_all_cmds():
>>>>>>>      d = _builtin_commands()
>>>>>>>      if plugins_override:
>> So I'm trying to say that this variable is still used in the code I
>> reviewed, but isn't declared as a parameter any more. Maybe you've
>> changed the code since ...
> 
> Oh! I get it now. Changed my mind in some code changes;  I'll put the
> parameter back as the easiest way to fix.

:-)

>>> remaining issues:
>>>  - do we need to warn people off from using the hooks
>> We don't need to warn them off - just let them know that they aren't
>> *required* to use them to register a command in a plugin.
> 
> Ok. I'm not sure how best to get the message across though:- do you
> think just mentioning it in the docs for (say) get_command is enough?

Yep - that's fine.

Ian C.