new file:   unit_tests.ods
	Added file containing tests for proving functionality of ab3418_commudp
modified:   ab3418_libudp.c
modified:   ab3418_libudp.h
	Added build_sigplanmsg for building SigPlanMessage, to be sent via UDP to MRP_TrafficControl and other modules
	Mofified build_spat:
		Added code for determining phase sequence and then max & min times to next phase
modified:   ab3418commudp.c
modified:   ab3418commudp.h
	Added call to build_sigplanmsg when request is received from MRP_TrafficControl, and its
	UDP response to that.