function isComposite( x ) {
	return Boolean( addon( x ) );
}
Returns a boolean indicating whether a number is a composite.

@private
@param {number} x - value to test
@returns {boolean} boolean indicating whether the number is composite

@example
var bool = isComposite( 4.0 );
// returns true

@example
var bool = isComposite( 5.0 );
// returns false