mercurial/helptext/deprecated.txt

branchmap: add a cache validation cache, avoid expensive re-hash on every use

In a pathological `hg log` case, we end up executing the branchmap validity
checking twice per commit displayed. Or maybe we always do, and I just noticed
because it's really slow in this repo for some reason.

Before:
```
  Time (mean ± σ):      9.816 s ±  0.071 s    [User: 9.435 s, System: 0.392 s]

  Range (min … max):    9.709 s …  9.920 s
```

After:
```
  Time (mean ± σ):      8.671 s ±  0.078 s    [User: 8.309 s, System: 0.392 s]

  Range (min … max):    8.594 s …  8.816 s
```

Differential Revision: https://phab.mercurial-scm.org/D9023

Mercurial evolves over time, some features, options, commands may be replaced by
better and more secure alternatives. This topic will help you migrating your
existing usage and/or configuration to newer features.

Commands
========

The following commands are still available but their use are not recommended:

``locate``

This command has been replaced by `hg files`.

``parents``

This command can be replaced by `hg summary` or `hg log` with appropriate
revsets. See `hg help revsets` for more information.

``tip``

The recommended alternative is `hg heads`.

Options
=======

``web.allowpull``
    Renamed to `allow-pull`.

``web.allow_push``
    Renamed to `allow-push`.