'PSO_2012.R': improved performance, by removing colnames and rownames to X, V, X.neighbours and Xt.fitness

'hydroPSO' function: argument 'method' now allows 'canonical'. 'fn' argument now can be function or character

hydroPSO: when 'out.with.fit.iter=TRUE, the number of iterations returned correspond to the effective number carried out, not to 'maxit'