- Modified the export scripts to use the right command, which is now
'export', not '_query', although '_query' is now an alias for backward
compatibility.
- Renamed all holiday files to include a locale, rather than just
a country code.
- Enhanced update-holidays.pl add-on script to support regions,
provide better error handling, error on missing Perl module,
warnings on unavailable data, and help text.
- Updated documentation accordingly.
- Incorporated (most of the) feedback from John's review of the code.
Got stuck on replacing 'import commands' with 'import subprocess',
and all that entails.
