[MERGE] improved help on storage formats

[Ian Clatworthy]

Matthew D. Fuller wrote:
> On Thu, Dec 11, 2008 at 06:10:18PM +1000 I heard the voice of
> Ian Clatworthy, and lo! it spake thus:
>> This patch improves the help by:
> 
> This is a very good and necessary thing to do.  However...

Matthew/Stephen,

[snip]

Thanks for a heap of suggestions for improvements. I like many
of them but I'm against a separate topic for experimental formats
- it ought to be just one most of the time after the rich-root
duality goes.

So I propose the following topics:

* formats - high level explanation, decision tree, rich root
  explanation
* current-formats - Matthew's list
* other-formats - experimental & deprecated stuff

That will work well in the User Reference I think: the first
topic will appear under "Concepts" and the latter topics will
appear under "Lists".

I'll put together a new patch along those lines unless I here
objections otherwise.

Ian C.