MCMC algo written from scratch (Functions_MCMC)

Many wrapper to allow generic functions to be applied systematically for a given model/dataset/parameters without passing it as parameter
Maybe it adds confusion to the code and is not necessary ?
Negative numbers returned by odesolver are set equal to 0
If MCMC sampling gives Inf for a parameter, it is automatically not accepted (to avoid likelihood = NA)
Regular message "DLSODA corrector convergence failed repeatedly" see if it's worrying and should be fixed
TODO : format results to allow the use of BayesianTools diagnostics plots