changegroup: add bundlecaps back Commit 282b288aa20c333c removed the unused bundlecaps argument from the changegroup code. While it is unused in core Mercurial, it was an important feature for the remotefilelog extension because it allowed the exchange layer to communicate to the changegroup packer that this was a shallow repo and that filelogs should not be included. Without bundlecaps, there is currently no other way to pass that information along without a more extensive refactor of exchange, bundle, and changegroup code. This patch backs out the original removal, and merges it with some recent changes to changegroup apis.