support workflow_id being set in log_history

A workflow can now be tracked in the log table, removing the need for
the job table to exist.

	modified:   Accessory/lib/CoGe/Accessory/Web.pm
add elapsed time helper function

Add format_time_diff function to format an elapsed time to a human
readable string.

	modified:   Accessory/lib/CoGe/Accessory/Utils.pm
add workflow logging for analysis tools

	modified:   web/CoGeBlast_new.pl
	modified:   web/SynFind_new.pl
	modified:   web/SynMap.pl