context: use manifest.walk() instead of manifest.match() to get file list
The former doesn't create a whole extra manifest in order to produce the
matching file list, which is all we actually cared about here. Sigh.
Differential Revision: https://phab.mercurial-scm.org/D8080
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This command has been replaced by `hg files`.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`.