History
+2018/03/16: Version 6.8.0
+
+2018/03/12: add doc/CALLOUTS.BUILTIN for builtin callouts
+2018/03/08: allow abbreviated notation for callouts (?(*name)..|..) (?(?{...})..|..)
+2018/03/02: NEW API: move onigenc_strdup() from regenc.h to oniguruma.h
+2018/02/21: remove all USE_COMBINATION_EXPLOSION_CHECK
+2018/02/15: fix #78: bad definition of PV_()
+2018/02/14: add configure option --enable-posix-api (for #77)
+2018/02/08: implement callouts of name
+2018/02/01: implement callouts of contents
+2018/01/30: define ONIGURUMA_VERSION_INT
+2018/01/29: enable USE_TRY_IN_MATCH_LIMIT by default
+2018/01/29: NEW API: onig_search_with_param() onig_match_with_param()
+2018/01/26: remove include windows.h from oniguruma.h
+
2018/01/26: Version 6.7.1
2018/01/25: disable USE_TRY_IN_MATCH_LIMIT by default