Completed bcp_server.

Task @T56 : This completes the bcp_server class and unit test. Runs
cleanly, reliably picks up connections, creates new bot_mk1 objects
and adds them to a running simulation. Tested by starting a sim_core,
making 10 connections at a pace of 1 every 5 ms, then examining the
simulation output to make sure the new bots were inserted properly.
Unit tested and ready to go.