Calculates meu, sigma and prior based on the updated probability weight matrix.
maximisation_mv(data, weights, meu, sigma, prior, num_clusters, num_data)
(matrix): The input data.
(matrix): The probability weight matrix.
(matrix): The matrix of meu.
(list): The list of sigma (co-variance matrices).
(vector): The vector of priors.
(numeric): The number of clusters.
(numeric): The total number of observations in the data.
Updated values for meu, sigma and prior.