Improve tracing of estream.
* src/gpgrt-int.h (trace_errno): Add new parameter. Adjust all users. * src/init.c (trace_fp, trace_with_errno, trace_missing_lf) (trace_prefix_done): New vars. (_gpgrt_internal_trace_begin): Add arg WITH_ERRNO. Open a trace file on first use. Init new vars. (print_internal_trace_prefix): New. * src/estream.c, src/w32-estream.c: Improve tracing.
- Signed-off-by: Werner Koch <wk@gnupg.org>