mlsnorm returns an object of class
univariateML.
This is a named numeric vector with maximum likelihood estimates for
the parameters mean, sd, xi and the following attributes:
- model
- The name of the model. 
- density
- The density associated with the estimates. 
- logLik
- The loglikelihood at the maximum. 
- support
- The support of the density. 
- n
- The number of observations. 
- call
- The call as captured my - match.call