bugfix: use of "ngx.flush(true)" with the "limit_rate" config directive or the $limit_rate variable may hang the request forever for large volumn of output data. thanks Shafreeck Sea for the report in #430.
feature: ngx.flush(true) can now wait on delayed events due to nginx's limit_rate config directive or "$limit_rate" variable settings. thanks Shafreeck Sea for the original patch in #432.