redo date.rb (most) parts in native #5076
still using JODA but all of the JI stuff in date.rb is gone behind ext classes, motivation :
some parts were already in native (formatting) so the base setup was already there.
NOTE: in MRI pretty much all of the date.rb is in native - so there's still space for improvement.
p.s. left behind one minor suite failure (argument validation
needs rebase (waiting for tests) but would like to get this in so I can spent time testing + adding JI stuff.
... this is simply distated by MRI's test suite we do not handle "big-integer" but that shouldn't matter for real-world
esp. since numeric handling through code-base feels a bit inconsistent
NOTE: MRI does not care for `Time.local` re-definition with `date.to_time`
... driven by one of the last failures -> strftime-ing pico-secs precision