Use new Unicode 6.2 beta

Use new Unicode 6.2 beta

These supposedly are the final data files for 6.2.  Earlier changes
originally proposed for 6.2 have been deferred until a later release.
Thus there is no change in the general category of ASCII characters in
these files from what they were in 6.1 and earlier, unlike what had been
proposed.

Unlike the previous experimental beta, code is now in place in Perl to
handle the revised definition of \X in 6.2.  The current working draft
of that definition is at http://unicode.org/draft/reports/tr29/tr29.html