config: add sanity assert that files are opened as binary
This helps with some debugging in Python 3, and shouldn't hurt
anything in Python 2. The unusual construction using getattr is done
so that StringIO/BytesIO instances can be used as well as real files.
# 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