.editorconfig

run-tests: organize options into argument groups

And sort arguments so help output is more legible.

There are probably a ton of ways to group things. I tried to
picture the test harness as a pipeline and attempted to draw boundaries
around stages in that pipeline to create the groupings.

Differential Revision: https://phab.mercurial-scm.org/D1475

# 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