Add Hull's method for handling path-constraints

[msparapa]

Dr Bolender brought Hull's method for implementing path constraints to my attention. The book is here and the method is on page 299. It appears to be most similar to Mall's Eps-Trig with sines and cosines. This is worth implementing since it'll be fairly easy with out current setup. It also might work with one-sided path-constraints, but I honestly haven't delved too far into the method.