Log Message:
Update to version 2.16.

Changes since last packaged version (2.14):

2.16  Oct 30 2006
      - Added test/fix for bad GroupTags option (report from Lee Goddard)
      - Added new_hashref() hook method
      - refactored cache save/restore methods for easier overriding

2.15  Oct 03 2006
      - Makefile.PL changes: reject known-bad PurePerl and RTF parser modules;
        default to XML::SAX::Expat if no parser installed
      - allow '.' characters in variable names (suggested by Cosimo Streppone)
      - fix output of undefs in arrayrefs with SuppressEmpty (reported by
        かんな - Kanna)
      - tidy up code and docs around lexical filehandle passed to OutputFile
        (report from Helge Sauer)
      - reduce memory usage by passing XML strings by reference (patch from
        Dan Sully)