[PATCH 1 of 2] extensions: extract descriptions at build time

[Cedric Duval]

Dan Villiom Podlaski Christiansen wrote:
> I suspect Martin was referring to third-party extensions, such as  
> hgsubversion. Allowing the extensions topic to list and describe third  
> party extensions too would make it much more valuable, in my opinion.  
> Especially in situations where system administrators or package managers 
> install other extensions.

Yes, that's what I was referring to (packaged unofficial extensions) in
the following paragraph and I agree that it would be useful to support it.
That is what I aim to do with having both build-time and run-time
descriptions extraction.

> basically, I just changed the disabled() method to optionally return
> the full description, and used that as a another final fallback for
> finding a help page.

Another interesting thing for post-1.3. :) (might not always turn up the
same as shows up once enabled though, when an extension and a command
share the same name - usually the latter has precedence). Might also be
nice to handle unambiguous shortcuts like is done for commands, for
extensions and additional topics.

> The patch is attached below.

(you might want to use patchbomb or put patches in the body, would make
for easier reviewing :) )

-- 
Cédric