formatter: rename {abspath}/{file} to {path}, and drop relative {path} (BC)
Note that {path} in status is either relative-to-cwd or repository-absolute
depending on the command argument and config knob, which can't be reproduced
by using the {path|relpath} filter. The default template is updated to always
use a relative path.
.. bc::
``{abspath}`` and ``{file}`` in generic templates are renamed to ``{path}``.
Any ``{path}`` is a repository-absolute path. Use ``{path|relpath}`` to
convert it to a filesystem path.