pyneqsys provides a convenience class for representing and solving non-linear
equation systems from symbolic expressions (provided e.g. with the help of
SymPy).

The numerical root finding is perfomed using either:
* scipy: scipy.optimize.root
* mpmath (arbitrary precision): mpmath.calculus.optimization.MDNewton
* kinsol (from SUNDIALS): pykinsol.solve
* nleq2 (ZIB library free for academic use): pynleq2.solve
* levmar (Levenberg-Marquardt): levmar.levmar

In addition to offering a unified interface to different solvers, pyneqsys can
also derive the Jacobian analytically (when using pyneqsys.SymbolicSys). This
is useful since doing so manually is widely recognized as both tedious and error
prone.