Add RiemannSurfacePathFactory stub.
Add RiemannSurfacePathFactory stub.

Add a stub for the RiemannSurfacePathFactory class and update
the documentation syntax of the function brought over from the
old, non-refactored code.

abelfunctions/abelfunctions,abelfunctions/abelfunctions,cswiercz/abelfunctions,cswiercz/abelfunctions,cswiercz/abelfunctions,abelfunctions/abelfunctions