Add paths around infinity.

monodromy() now calls path_segments_around_infinity() to
directly determine the monodromy group element about
infinity.
Fix permutation multiplication.

When permutation indices were switched to zero-based
indices, multiplication was not changed accordingly.
Initial implementation of fibre-based analytic continuation.

Also, a partial checkpoint to implementing the Deconinck -
van Hoeij technique.
Deconinck-van Hoeij continuation checkpoint.

Technique works with one example. (f=f2) Breaks on other
example. (f=f1)
Minor refactor.

With these minor changes, analytic continuation seems
to now work. Now need to finish converting plotting,
monodromy, and homology to the new continuation
scheme.
Verify monodromy works with f=f2.
Implement Smale's alpha theory in analytic continuation.

Smale's alpha theory is used to determine whether Newton's
method will converge. It can also be used to determine
whether or not two "approximate" solutions will converge
to distinct roots which is Key to preventing "branch
jumping" during analytic continuation. These techniques are
implemented.
Fix minor bug in RiemannSurfacePath.__init__().