Rename HashJoinOperator => LookupJoinOperator
Rename JoinHash to LookupSource

This is preparation for adding index joins

Extract LookupSourceSupplier from HashSupplier
Rename HashSupplier to SettableLookupSupplier
Change position from int to long in LookupSource
Add support for index joins
Add unit tests for index joins
Static import DateTimeZoneIndex.unpackChronology into DateTimeFunctions
Simplify date time field calculations

Add quarter of year date time file for consistency
Add utility method to get a DateTimeField for a chronology
Add date_add and date_diff for time and date types
Add date_trunc function
Remove century date time field