Seq Char not working with Unicode

[cdornan]

This seems to be a separate problem from #3 in that when I correct for that down stream Seq Char matching on unicode characters fails to work. As Seq Char is probably not being used much with the development of the text package the Seq Char API could just be mapped onto String operations. (Separately, regex-base should perhaps move to deprecate support for Seq Char.)

[audreyt]

Thanks & agreed.

Pull requests welcome :-) My day job as Digital Minister @ Taiwan unfortunately leaves relative little time for my FLOSS responsibilities.