Holiday now extends DateTime and HolidayCollection now can add Holiday objects relative to the easter date itself
Add tests to confirm that holiday objects can be compared with datetime objects.
Added new helper method to Bundesland which returns a HolidayCollection (Feiertage) with only local holidays in a Bundesland for a given year.
And another helper to get all holidays in a bundesland for a given year.
Removed previous additions to bundesland, doesn't really make sense to have those helpers in the first place.
Added an example to the readme and fixed a logical error in DayCalculator::getWorkdays() when no Bundesland is set.
Merge pull request #3 from timoschaefer/1.0

Merge branch '1.0'