newton.c example misinterprets pll_compute_likelihood_derivatives return value

[bcclaywell]

The Newton's method branch length optimization example (newton.c) appears to misinterpret what pll_compute_likelihood_derivatives returns here. It stores the return value as double opt_logl (optimized log-likelihood?) when in fact the function returns an int that as far as I can tell is a status code.

[xflouris]

thanks @bcclaywell , we forgot to update the example after a recent change in the derivative functions. I'll update the code beginning of next week.

[xflouris]

started working on this

[stamatak]

can we close this?