It seems just a matter of tuning b_max. Some trials show that in this
case, b_max=0.1 is probably good, the first task then converges within
10-15 iterations. More aggressive b_max=1.0 also works, but then there
is some overshoot and oscillation at first. Not sure that would be a
problem though, after all we're not going to try and control a robot
with the convergence trajectory.
Start splitting stuff into separate files and add a skeleton GTK2 app
for developing an interactive elastic bands demo and dev tool.
basic graphic and elastic structure in place