Perf: adding max

[mitra42]

I'm not sure, but I think can improve performance of sorting etc, by passing around some 'max' parameters. See #42

[mitra42]

• [ ] Contacts
  • [ ] sort and truncate should get sent shorter lists based
  • [ ] sorted_list_by_time_and_serial_number_range can tell us max viable now
  • [ ] compare contacts and spatial max viable now and take earliest
  • [ ] add max value to sorted_list_by_time_and_serial_number_range
• [ ] Spatial