Changes in numDeriv version 2009.2-1

  o argument zero.tol was added to grad, jacobian and genD, and is used to test
    if parameters are zero in order to determine if eps should be used in place
    of d.  Previous tests using == did not work for very small values.

  o defaults argument d to grad was 0.0001, but specification made it appear to
    be 0.1. Specification was changed to make default clear.

  o unnecessary hessian.default argument setting was removed (they are just
  passed to genD which duplicated the setting).

  o Some documentation links to [stats]numericDeriv mistakenly called 
     numericalDeriv were fixed.  
  

                  numDeriv version 2006.4-1

  o  First released version.