Note that this currently, this isn't implemented in the C++ standard
library. This means that date_order() will always return no_order,
causing this function to always return the default
DATE_FORMAT_DAY_MONTH_YEAR, as is the case before this commit too.
Once date_order() will be properly implemented in the standard library
someday, it will however start returning the right order for the current
locale, causing this function to start working as intended.
While OpenRCT2 already had code to look up the Steam path on macOS and Linux, it didn't look in the correct directory. This meant that it wouldn't detect the presence of RCT2, even if the user had downloaded it via the Steam Console.
Clang-format sees the text behind `#pragma region` as code and formats it. Instead of stating the copyright and date there, it's now in the comment block right below it. The text "Copyright" is left in the `#pragma region` line, as clang-format sees it as a single identifier.
I took the opportunity to normalize the dates, and add the copyright notice to the source files where it was missing them (except for third-party and the generated resources.h file).
