Log Message:
Update to 1.63

Upstream changes:
1.63      2014-06-11 21:58:18Z

        [FIXED]

        - incorrect error messages fixed, when $@ is clobbered when Carp
          wasn't loaded (GH#30, GH#31, Hilko Bengen)

        [CHANGED]

        - now checking for, and erroring on, duplicate keys found in a hash
          (GH#32, Hilko Bengen)