bugfix: memory invalid reads might happen when ngx.flush(true) was used: the "ctx" struct could get freed in the middle of processing and we should save the state explicitly on the C stack.
fixed bad request header lines in the tests in 116-raw-req-socket.t, which caused test bailout in the "check leak" testing mode.
bugfix: fixed most of the compiler warnings from the MinGW C compiler, some of which are real overflow issues. thanks Edwin Cleton for the report.