Add topography as an event object type, we use this to notify applets
about dynamic obstacles.  Some event-sched fixes are also included.

	* lib/libtb/tbdefs.h, lib/libtb/tbdefs.c: Add TOPOGRAPHY object
	and CREATE event.

	* robots/emc/emcd.c: Some cleanup for the events that get sent for
	dynamic obstacles.

	* tbsetup/ns2ir/node.tcl, tbsetup/ns2ir/sim.tcl.in,
	tbsetup/ns2ir/topography.tcl: Add Topography's to the virt_agents
	table.

	* event/sched/error-record.c: Fix the format for the filenames
	generated by the program-agent.

	* event/sched/event-sched.c: Mark the start of TIME, change how
	rmcd/vmcd get restarted, and fix the ordering of some events on
	startup.

	* event/sched/simulator-agent.h, event/sched/simulator-agent.cc:
	Record when TIME starts, change how the report is generated, and
	the current time to log messages.

	* event/sched/rpc.h, event/sched/rpc.cc: Add the "virtual"
	topography name to the emcd.config, it's used when sending events
	concerning dynamic obstacles.