function isPositiveInteger( x ) {
	return Boolean( addon( x ) );
}
Tests if a finite double-precision floating-point number is a positive integer.

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

@example
var bool = isPositiveInteger( 3.0 );
// returns true

@example
var bool = isPositiveInteger( -4.0 );
// returns false