Changelog:
* NEW API: ONIG_OPTION_CALLBACK_EACH_MATCH
* NEW API: ONIG_OPTION_IGNORECASE_IS_ASCII
* NEW API: ONIG_SYNTAX_PYTHON
* Fixed some problems found by OSS-Fuzz
* fix: replace UChar to OnigUChar in oniguruma.h
Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>