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.
Class  that combines the total_num_inputs individual patterns and creates a single pattern that it returns.  For instance, Composite can merge the individual patterns into a single pattern using a variety of operators like add or maximum, while Selector can choose one out of a given set of patterns.