update_params0: The initialization parameters, corresponding to predicting a changepoint (run length=0)
update_paramsT: The vectors of parameters corresponding to each possible run length, updated with each incoming data point
Rlength: the length of the current vector of possible run lengths
skippt: set to FALSE if not needing to accommodate skipping missed points during the update of parameters
Returns
The list of the parameters for gaussians corresponding to each possible runlength up to the current data point. Lengths of vectors should correspond the length of the R vector ("run length vector")