Added a script which exposes two bottlenecks in the hessian generation: the detection of symmetric sparsity patterns, which needs starColoring for efficiency, as well as the starColoring algorthm ifself
Added note on properties of the Hessian sparsity pattern in the hessian_sparsity_bottlecks.py example
Merge branch 'develop' of github.com:casadi/casadi into develop