integration of new spline toolbox

[rubenvanparys]

omg-tools is completely refactored in order to work with the new spline toolbox (on branch erik_splines). Following issues are still present:

• [ ] General performance issue
• [ ] Serious performance issue with bicycle, agv (reverse bicycle) and honomic with orientation (I've added related examples to the benchmark_examples)
• [ ] Casadi codegen when using sorter node
• [ ] Casadi SX expansion when using sorter node