function binomcoefln( n, k ) {
	return addon( n, k );
}
Computes the natural logarithm of the binomial coefficient of two integers.

@private
@param {integer} n - input value
@param {integer} k - second input value
@returns {number} function value

@example
var v = binomcoefln( 8, 2 );
// returns ~3.332

@example
var v = binomcoefln( 0, 0 );
// returns 0.0

@example
var v = binomcoefln( -4, 2 );
// returns ~2.303

@example
var v = binomcoefln( 88, 3 );
// returns ~11.606