[R-sig-ME] glmmADMB fails to fit poisson data

[dave fournier]

On the other hand maybe the code never will write itself. The following 
change to the Poisson
model in glmmadmb  using the log(1_+y_i) transformation to get good 
initial parameter estimates
converges nicely on this data set.

     case 0:   // Poisson
       if (cph<2)
         tmpl=-square(log(1.0+y(_i,1))-log(1.0+lambda));
       else
         tmpl= log_density_poisson(y(_i,1),lambda);
       break;
     case 1:   // Binomial: y(_i,1)=#successes, y(_i,2)=#failures,