relnotes: copy "next" to "5.7" and clear "next"

The same procedure as every year^Wcycle.

Differential Revision: https://phab.mercurial-scm.org/D9909

relnotes/next

@@ -1,59 +1,8 b''
 == New Features ==
 
- * There is a new config section for templates used by hg commands. It
-   is called `[command-templates]`. Some existing config options have
-   been deprecated in favor of config options in the new
-   section. These are: `ui.logtemplate` to `command-templates.log`,
-   `ui.graphnodetemplate` to `command-templates.graphnode`,
-   `ui.mergemarkertemplate` to `command-templates.mergemarker`,
-   `ui.pre-merge-tool-output-template` to
-   `command-templates.pre-merge-tool-output`.
-
- * There is a new set of config options for the template used for the
-   one-line commit summary displayed by various commands, such as `hg
-   rebase`. The main one is `command-templates.oneline-summary`. That
-   can be overridden per command with
-   `command-templates.oneline-summary.<command>`, where `<command>`
-   can be e.g. `rebase`. As part of this effort, the default format
-   from `hg rebase` was reorganized a bit.
-
- * `hg strip`, from the strip extension, is now a core command, `hg
-   debugstrip`. The extension remains for compatibility.
-
- * `hg diff` and `hg extdiff` now support `--from <rev>` and `--to <rev>`
-   arguments as clearer alternatives to `-r <revs>`. `-r <revs>` has been
-   deprecated.
-
- * The memory footprint per changeset during pull/unbundle
-   operations has been further reduced.
-
- * There is a new internal merge tool called `internal:mergediff` (can
-   be set as the value for the `merge` config in the `[ui]`
-   section). It resolves merges the same was as `internal:merge` and
-   `internal:merge3`, but it shows conflicts differently. Instead of
-   showing 2 or 3 snapshots of the conflicting pieces of code, it
-   shows one snapshot and a diff. This may be useful when at least one
-   side of the conflict is similar to the base. The new marker style
-   is also supported by "premerge" as
-   `merge-tools.<tool>.premerge=keep-mergediff`.
-
- * External hooks are now called with `HGPLAIN=1` preset.  This has the side
-   effect of ignoring aliases, templates, revsetaliases, and a few other config
-   options in any `hg` command spawned by the hook.  The previous behavior
-   can be restored by setting HGPLAINEXCEPT appropriately in the parent process.
-   See `hg help environment` for the list of items, and how to set it.
-
- * The `branchmap` cache is updated more intelligently and can be
-   significantly faster for repositories with many branches and changesets.
-
 
 == New Experimental Features ==
 
-* `experimental.single-head-per-branch:public-changes-only` can be used
-  restrict the single head check to public revision. This is useful for
-  overlay repository that have both a publishing and non-publishing view
-  of the same storage.
-
 
 == Bug Fixes ==
 
@@ -61,9 +10,6 b''
 
 == Backwards Compatibility Changes ==
 
- * `--force-lock` and `--force-wlock` options on `hg debuglock` command are
-   renamed to `--force-free-lock` and `--force-free-wlock` respectively.
-
 
 == Internal API Changes ==