Added PatternCoordinator class which returns a set of coordinated pattern generators

A PatternCoordinator is a set of coordinated pattern generators.
The pattern generators are named according to the labels parameter.
The dimensions to be returned are specified with the dims parameter.
PatternGenerators are first instantiated with the parameters specified in input_parameters, and then subclasses of ValueCoordinator are applied to modify the properties of these generators.
Base seed for the input patterns. Each numbered input on each of the various labels will have a different random seed, but all of these seeds include this master seed value, and so changing it will alter the streams of all the random input pattern parameters.