revset: add support for p2(wdir()) to get second parent of working directory
This adds support for finding the second parent of working directory using the
p2 predicate.
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true