PRMethods - D-Hondt, Sainte-Lague, and Modified Sainte-Lague Methods for Seat Allocation

Calculates seat allocation using the D-Hondt method, Sainte-Lague method, and Modified Sainte-Lague method, all commonly used in proportional representation electoral systems. For more information on these methods, see Michael Gallagher (1991)<doi:10.1016/0261-3794(91)90004-C>.