output: Collects and saves output.
In EDISON: Network Reconstruction and Changepoint Detection

This function collects the network, changepoint and hyperparameter samples taken from the MCMC simulation, and saves them to a file if appropriate.

1	output(counters, listStock, GLOBvar, HYPERvar, OUTvar)

`counters`	List of counters for the number of moves that have been proposed and accepted.
`listStock`	Network, changepoint and hyperparameter samples.
`GLOBvar`	Global variables of the MCMC simulation.
`HYPERvar`	Hyperparameter variables.
`OUTvar`	Output variables, including the output file.

Returns a list with an element for each target node which is also a list. Each sublist containts the elements:

`cp_samples`	Changepoint samples, a NumSamples by MaxNumChangePoints matrix.
`edge_samples`	Network samples (with regression parameters), a NumSamples by (NumSegs * NumNodes) matrix.
`target`	The target node for this subnetwork.
`hyper_samples`	Information sharing prior hyperparameter samples, a NumSamples by NumHyperParams matrix.
`sampled`	Sampled iterations.
`counters`	Counters for the number of proposed and accepted moves.