- remove __attribute__(format) checker for UTF8 char type printf becuase it forcely require the type of format string is const char*, rather than const char8_t*, and I can not use any switches to remove this.
- delete useless macro and header in clap manual.
- move utf8 stream and format patch from string to patch namespace.
- add ordinay format alias and utf8 format in our format patch.
- add char8_t and char inter-cast in string reinterpret namespace.
- fix bug of utf8 formatter.
- add test for utf8 format.
