'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'

'hydroPSO': immproved checking of some arguments; 'random.update' only used when 'best.update'=async, and more and better examples. 'text\_functions': corrected name of the 'rastringin' function, and corrected definition of the 'shafferF6' function

new 'random.update' parameter for the 'control' variable, in order to allow random update of personal/global best

hydroPSO: default value of the inertia weight 'IW' was changed from (linearly decreasing) IW.w= c(1.2, 0.4) to 'IW.w=1/(2*log(2))'

hydroPSO: fixed small bug related to improper PSO evolution when 'best.update==async'. source code was tidy up. Added '...'  parameter.

'c1, c2, lambda are now written only once in the 'PSO_logfile.txt' file when the time-varying option is chosen

'velocities' variable removed. Writing of 'Velocities.txt' and 'Particles.txt' files moved to the begining of the 'Particles Loop (j)' loop