Support multi-byte terminator

I'm parsing some CSV files that use the "record delemiter"/terminator `\x02\n`. I can't use `\n` as terminator, since `\n` may occur in record field values.

Another bug is that I don't get any records at all if I choose `\x02` as the terminator. My suspicion is that this library always does something special for `\n` even if it's not set as the terminator.