[merge] split out repository formats

[John Arbash Meinel]

Martin Pool wrote:
> This splits some old formats into a bzrlib.repofmt submodule, and allows
> for them to be lazily loaded from there.
> 
> I have a followon that moves the other formats but this is quite
> textually (though not conceptually) large already.
> 

I would have probably put the base class and the registry in
bzrlib/repofmt/__init__.py, but this isn't a huge deal.

...


You also didn't mention a few other things that you did. Namely getting
rid of InterWeaveRepo and changing bzrdir.open_repository() for certain
formats to create_repository() for all formats.

I think Robert brought up a reasonable concern about whether you could
upgrade a Weave to a knit.

There probably are not many people still using a Weave repo because of
the warning. But then again has Dapper had an official upgrade to bzr?
Because 0.8.2 was perfectly ok using Weave formats. And back in Nov I
know some of the distro people were still using Weaves because they just
hadn't needed to upgrade yet. (For small projects they work okay).

So I really like the idea, but I feel your description of what is going
on is incomplete, and I'm not sure if I've missed something in the large
patch.

John
=:->