bundle-spec: add an official method to format a spec into a string This will be useful for automatic-clonebundles.

clonebundles: adds a auto-generate.serve-inline option This new option disable the "external" serving of auto generated bundle in favor of using the new "inline bundle" feature that allow serving such bundle through the mercurial protocol. This is a less efficient, but very easy to setup way to start using clone bundle.

clone-bundle: only add the REQUIRESNI bit for http(s) we don't needs it for `peer-bundle-cache://` for example

stream-clone: add a stream-v3 variant of test-persistent-nodemap.t This will be useful to track and validate future changes to the stream-v3 protocol.

stream-clone: split the stream part out of test-persistent-nodemap.t We want to test multiple variants, so let's make it an independent test. Small adaptations and simplifications are needed in the test output as the tested repository is now shorter.

stream-clone: explicitly split debug test output for application per version Altering the format may introduce significant changes in output and in order. It is going to be simpler to deal with explicitly different blocks for the output.

stream-clone: add a v3 version of the protocol This new version is less rigid regarding the extract number of files and number of bytes to be actually transfered, it also lays the groundwork for other improvements. The format stays experimental, but this is an interesting base to build upon.