gnu-indent: option depreciation

Depreciates the default names option in favour of with-default-names, adds a test.
I've just killed the option for now. The only reason I can think of for the failure is that ``` gindent --version ``` isn't an officially-detailed command as far as I can see, even though gnu-indent responds with the version information as expected. Perhaps that's the issue, but I'm not sure on that to be honest.