* Fix unicode test

* Add xchar support to chrono formatter

* Replace strftime with std::time_put

* Add std::locale support to std::tm formatter

* Use predefined names and formats for C-locale

* Performance improvement

* Make locale-independent and C locale formats consistent among platforms

Switch internal year calculations to long long

When build the docs for debian package, it uses a sphinx building
helper, which does a sanity check for the output.

The sanity check complains missing data-url_root attribute in the
js tag. So this patch changes the js tag to use the same function like
the origin basic theme, which adds additional information like
data-url_root.

Ref: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=997437

Requested changes

fix: remaining ifdefs