[EM] Clarifying Bias-Free definition

[Michael Ossipoff]

Bias-Free is a divisor method, in the strictest sense of the word. You know 
how the divisor methods work, so I won't go into that, except to say that 
they all choose a rounding point between consecutive integers a & b, by a 
formula that specifies a function of a and b.

For example, with Webster the function is (a+b)/2. With Hill it's sqr(a*b). 
With Jefferson it's b. With Adams it's a.

So, with Bias-Free, it's ((b^b)/(a^a))(1/e).

Mike Ossipoff