Faster matrix algebra for Laplace marginals

[athowes]

• Scope out the possibility for more control over the evaluation of MakeADFun, especially the matrix algebra. This can be started by first understanding the internals of MakeADFun. Could it be replaced with relying on and and the Laplace approximation computed outside of TMB, with parts replaced to speed it up as required
  • Put MakeADFun into development script
  • Click through MakeADFun and write comments as to what is doing which part. Try to find the part which is doing the matrix algebra.