should not use '\t' as header separator

[byb121]

This line returns a header with the literal string \t as a separator. According to SAM format, that string is also allowed in a tag value. If a tag value has it, it is an extreme case though, the subroutine will return an unusable header line.

I'm wondering if we can just use a tab as separator, or probably a new line, or just return an array if neither of them works?