2008/3/10: changes from version 0.4-0 to 0.5-0

- new method for tensor estimation 
  method=="regularized"  uses the parametrization from Koay et.al. (2006)

- alternative statistical penalty based on difference of log-likelihood values 
  (this will be the only available method for method=="nonlinear" and method=="regularized"
  since it eliminates the need to distinguish between covariance matrices for D and rho)
  