Binomial_adaboost always gives NOTE on coefficients

[mayrandy]

The classical Binomial(type = "adaboost") always prints the NOTE

NOTE: Coefficients from a Binomial model are half the size of coefficients
 from a model fitted via glm(... , family = 'binomial').
See Warning section in ?coef.mboost

although this is only the case for link = "logit", see also #63 .