a distance argument.

- Simplified some of the code a bit by making it use ordered_sample_pair
- Broke backwards compatibility, the syntax for passing order_by_distance
  and order_by_index to std::sort() is now slightly different since these
  functions are now templates.  This allows them to work on any kind of
  sample_pair or ordered_sample_pair object.

value instead of float.

of a block of memory.

object.

to detect invalid serialization.

than std::pair to represent hostname/port combos.

logic somewhat.