Division bug in logistic likelihood function fixed.
Parameter 'nargout' added to the function 'predict'. Special treatment for classification likelihood functions added. Printing iteration results during optimization process in the GP's 'fit' function added.
Markov Chain Monte Carlo (MCMC) inference method added.
Minor bugs in MCMC inference method fixed.
Laplace approximation of Gauss, Erf and Logistic likelihood functions implemented.