This module provides a function to solve generalized Pell Equations, using the "LMM Algorithm" described by John P. Robertson in http://www.jpr2718.org/pell.pdf. A generalized Pell Equation is a diophantine equation of the form x^2 - dy^2 = n, where d is a positive integer which is not a square and where n is a non-zero integer. We are looking for solutions (x,y), where x and y are non-negative integers.