debug: use InputError instead of CommandError for validating arguments

clonebundle: add a `filter_bundle_url` function This function does nothing by default, but give extension the opportunity to alter the URL, typically, this could be used to inject authentication token when serving clone bundle for private repositories.

clonebundles: move the manifest reading in a dedicated function We are about to make the logic more advanced to help hosting solution, so we need to centralize it first.

doc: format argument for date uses strftime format string (issue6818)

clonebundles: filter out invalid schemes instead of failing on them Previously, an invalid clonebundle scheme would result in a failed clone. By specifying a list of schemes we support, we can make sure adding a new scheme (like the one for inline clonebundles) does not result in clones failing for older clients.

clonebundles: demonstrate bad behaviour when unknown scheme is present

rhg: support `rhg files` with `ui.relative-paths=false`

rhg: make `rhg files` work if `ui.relative-files=true` is specified

rhg: test `rhg files --config ui.relative-paths ...` Add some tests. All of these are falling back for now, will be fixed in follow-up commits.

cleanup: simplify code