DecisionTool --> Abstract (factory) class for algorithm to choose when
	     to take samples.  SmartSampler calls genDT, and uses the
	     interface in DecisionTool.hh.

Other specific DecisionTool implementations reside in their own
subdirectories.  

SimpleThreshold --> Simple tool for triggering on a fixed (in
		configuration file) threshold of any of the
		measurement types.  Intended for interface testing and
		to serve as a template for generating new tools.

ClusterHMM --> Tool for choosing when to fire gulpers based on an
	     HMM from which the cluster server provides
	     "observations".

FrontMomentum --> Tool for finding upwelling fronts based on momentum
	      of the data differential one profile to the next.
