Add method to converge exactly onto bifurcation points
For bifurcation tracking (#19), branch switching or simply for localizing bifurcation points exactly, we need some method to converge onto these points.
This could happen by either:
- bisection method in [s, s+ds] until the corresponding eigenvalue vanishes exactly.
- solving the augmented system with an sufficiently good inital guess for the eigenvector, as in (#19)
Maybe we can implement both methods and compare?