need to bring in changes for Laplace/AGHQ from nimble

[paciorek]

We're now proceeding to make some changes to Laplace/AGHQ on nimble as we're planning to improve that functionality for nimble 1.3.0 (in particular not using BFGS for inner optimization). The thought is that that will be ready to go before the INLA work. But it also means that this repo will need to incorporate any changes made in nimble.