Event system documentation and tweaks:

	* event/sched/event-sched.c: The snapshot event got left out of
	the list of events that send back a complete event.  If a top
	level sequence stops with an error, automatically send a report.

	* event/sched/group-agent.c, event/sched/timeline-agent.c: When
	handling a complete event, return true if the event was consumed.

	* event/sched/node-agent.cc: Clean the "/local/logs" loghole on
	the node before taking a snapshot of the disk image.

	* event/sched/simulator-agent.cc, event/sched/simulator-agent.h:
	Made send_report non-static so it can be called when a sequence
	errors out.  Actually check the clear flag when dumping report
	data.

	* lib/libtb/tbdefs.c: Add a comment about updating the event
	scheduler when a new object type is added.

	* tbsetup/ns2ir/sim.tcl.in: Check the OSIDs passed to the "reload"
	and "snapshot-to" events.

	* utils/loghole.1: Mention early and often the directories that
	gets sync'd.  Document the 'change' action and new options for
	'clean'.

	* utils/loghole.in: Use rsync's '--include-from' option so we
	don't have to run rsync separately for each directory.  Add a
	'change' action that lets people mess with the metadata of an
	existing archive.  Make the 'clean' action also remove log files
	on the nodes.  Only rsync node's whose OS's support ssh.  Grab
	logs from delay nodes.

	* www/tutorial/advanced.html: Update the program agent examples to
	use the new form.

	* www/tutorial/eventsystem.html: First cut at an event system
	reference manual that includes sequences, timelines, and other
	new features.

	* www/tutorial/loghole.html: Just a pointer to the man page on ops
	for now.

	* www/tutorial/nscommands.html: Add a section about capturing
	parameters from the 'opt' array.

	* xmlrpc/emulabserver.py.in: Add an osid.info() method that
	returns information about a single OSID.