Optimize abs_mean_curv by minimizing computation by caching sub result in for-loop.
Optimize CurvatureEngergy::delta_energy by reusing vector<vec3d> objects instead of recreating them. This gives a speedup of 2x (and produces the same result)
Optimize priority queue optimization: Only add elements if updated. Only work on one of the halfedges. Gives x6 speedup.
Merge pull request #2 from mortennobel/master

CurvatureEnergy::delta_energy optimization