exthelper: support the option argument when registering a command
Largefiles uses this 5th argument with push and pull, so this will be tested in
the next commit. I assume the reason for unrolling and reforming the tuple in
each finalxxxsetup() is to validate that something proper was passed in when
registering. But it's better to explode when decorating than during the delayed
actual registration.
# 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
[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false