• Renamed namespace pegtl::ucs4 to pegtl::utf32 and generally adopted UTF-32 in all naming.
• Added experimental support for UTF-16 similar to the previously existing UTF-32 parsing rules.
• Added support for merging escaped UTF-16 surrogate pairs to pegtl/contrib/unescape.hh.
• Fixed incorrect handling of escaped UTF-16 surrogate pairs in the JSON examples.
• A state's S::success()-method can now have an extended signature to get access to the current apply_mode, action- and control class (template).
• The contrib/raw_string class template now calls Action<raw_string<...>::content>::apply() with the user's state(s).