Mistakes in examples in documentation about python-control

[murrayrm]

My only concern would be that some examples might require a lot of setup that would make it verbose and less useful. Setting up something like an LQR problem, for example. But if we can do these succinctly, then I agree that we should have the goal that examples execute (so nosetests --with-doctest returns no errors).

[cwrowley]

I agree about the potentially verbose setup. LQR is a good example too, because the calling syntax is complex, and not immediately obvious from the function's signature lqr(*args, **kwargs). However, in the LQR documentation, I think the "Examples" section could actually be removed, since the syntax is already illustrated earlier in the doc string. Maybe formatting something like this could work for other routines where the setup is complicated too.

[murrayrm]

Fixed in PR #228.