Repository and branch format descriptions - bug 264730

[Talden]

>> The basic flow of repository formats is:
> [... lots deleted ...]
>> So getting back to the Repository formats, we should have:
> [... 11 formats deleted ...]
>
> So remind me, who said that complaints that Bazaar has too many
> formats are misleading...? :-)

Do all the formats fall into the following categories?

1. THESE formats exist only for backwards compatibility - don't create
repos with them. (warnings issued?)
2. THIS format is the default. It is most widely supported as of now
(perhaps based on how broadly distributed versions of bazaar
supporting this format are). (the default - obviously)
3. THESE formats are newer and may become the default later. (hidden)
4. THESE formats are experimental.  Never use these on anything
important. (hidden and warnings issued)

We also need to provide stronger encouragement to move forward... Sure
it's nice to support all those old formats but perhaps we should be
removing support for anything but upgrading some of them and noting
'the last bazaar version that supported this format was X' so they can
go get an appropriate version later.  That is, supporting
branching/pushing/pulling/upgrading but not committing.

To help protect content for people putting repos into long-term
storage perhaps we need a well-defined and extensible stream-format
(ala something like but better than the Subversion dump format) to
export to that can be replayed into a modern repo format (or even
another tool).  Is this the intent of the fast-export/import?  Can we
start actively supporting such a format so that we can more
aggressively discontinue support for old repo formats?

--
Talden