subclasses of x++

[Eric Dean Tribble <tribble>]

The isSeparator and isLinebreak should be queries to the Attributes
object.  Since these Attributes object know the context of the
PacOBits, they know which characters are separators and linebreaks.
Thus if the values represent ascii characters, the Attributes object
will return true for spaces, tabs, etc.  In particular, the BitArry
and PacOBits know nothing about such distinctions.

dean