Legacy support

I think larsivi does this (to some degree) via the list of tickets? The tickets themselves should indicate whether something is a breaking change?

I think most of what you're asking is addressed by the PreviousReleases page. However, I am well aware that we generally don't have versioned docs tied to that, and that is more of a process problem than anything else. So this is not information that can be added to already made releases (the info doesn't exist), and probably not to the next either (beyond feeble attempts to document breaking changes).

I think I will move this to 0.99.7, and see if an effort to do this properly can be made from then on - not that breaking changes should be happen much more prior to 1.0 (at least not in the main parts ...).