update Directory Reference

Files
	expire_snapshots.h
	API for removing old snapshots from a table.
	fast_append.h
	pending_update.h
	set_snapshot.h
	Sets the current snapshot directly or by rolling back.
	snapshot_manager.h
	API for managing snapshots and snapshot references.
	snapshot_update.h
	update_location.h
	Updates the table location.
	update_partition_spec.h
	update_partition_statistics.h
	Updates table partition statistics.
	update_properties.h
	Updates table properties.
	update_schema.h
	update_snapshot_reference.h
	update_sort_order.h
	Updates the table sort order.
	update_statistics.h
	Updates table statistics.