Fix the grammatical genre of the festivities. And use a UTF-8 ligature.
If the year is 4000 or later, the roman number format defaults to
arabic digits instead of defaulting to undef.
Fix a typo in the test data.
For simplicity's sake, the behaviour of invalid %E and %O
sequences is different from DateTime::Calendar::FrenchRevolutionary.
It appears "as is" in the result string, instead of defaulting
to the E-less or O-less specifier.
Use %* as an alternate for %Ej. Compatibility with
DateTime::Calendar::Pataphysical.
Fix an "undef variable" warning when using year 4000 or after.
Stylistic issues and a bit more code coverage.
Still more code coverage.