function mode( p ) {
	return addon( p );
}
Returns the mode of a Bernoulli distribution.

@private
@param {Probability} p - success probability
@returns {NonNegativeInteger} mode

@example
var v = mode( 0.1 );
// returns 0

@example
var v = mode( 0.8 );
// returns 1

@example
var v = mode( 0.5 );
// returns 0

@example
var v = mode( 1.1 );
// returns NaN

@example
var v = mode( NaN );
// returns NaN