py3: ditch email.parser.BytesParser which appears to be plain crap As I said before, BytesParser is a thin wrapper over the unicode Parser, and it's too thin to return bytes back. Today, I found it does normalize newline characters to '\n's thanks to the careless use of TextIOWrapper. So, this patch replaces BytesParser with Parser + TextIOWrapper, and fix newline handling. Since I don't know what's the least bad encoding strategy here, I just copied it from BytesParser. I've moved new parse() function from pycompat, as it is no longer a trivial wrapper.