NLSP graphic output

Now you can use NLSP (non-linear solve) graphic output:
p = NLSP(f, x0, plot=True, ...)
p.connectIterFcn('df') # scipy.optimize.fsolve has no native iter func that could be connected to OO
#optional: provide gradient df
#p.df = ...
r = p.solve('scipy_fsolve')
(for other NLSP solvers that cannot handle df you should use p.connectIterFcn('f'), however, this is still buggy, maybe I will fix the 'f' case in future).

Let me also remember that you can use p.xlabel = 'time' (default), 'cputime', 'nIter' (case-unsensetive). Old-style p.graphics.xlabel works as well.

The dotted line in the picture is log10(p.contol)