GregorianCalendarManager:
-finished portation of calendar calculation logic
-changed GregorianGranularity to include reset calendar fields of GregorianCalendar
Calendar:
-fixed initialization cycle bug resulting in nullpointerexceptions down the line
GranularityAssociation:
-got rid of DualHashBidiMap
-replaced it with two separate instances of Hashtable
-external functionality still the same
GregorianCalendarManagerTest:
-added a few rudimentary tests (needs to be expanded further)