Changes in Version 1.1-7
  o The predict() function now returns the predicted probabilities in addition to the predicted category for categorical variables
  o Added a message for all estimation functions indicating where edge weights (if defined) can be found: fitobject$signs
  o Added a startup message with a link to report bugs
  o The predict() function now computes predicted values and a prediction error for each variable in the graph
  o The print() function now returns a small summary of the model type when printing a mgm object
  o Added subsampling scheme to evaluate edge-stability for non-time-varying models (MGM and mixed VAR)
      o Added summary() & plot() for the bootstrap object to summarize edge-stability
  o Added argument 'binary.sign': If binary.sign=TRUE, the sign of the interactions of all binary variables coded (0,1) with other binary variables and continuous variables will be returned in the sign matrix fit$signs
  
