[EM] Bucklin-Range cont'd

[Kristofer Munsterhjelm]

By combining the Bucklin-Range method with more STV-like logic (mainly 
only assigning voters when there are enough of them to give a new seat, 
and then redistributing surpluses), I've created party list 
(Webster-based) and candidate (Droop quota-based) multiwinner methods 
based on the Bucklin variant.

POC Python implementations can be found here: 
https://github.com/kristomu/voting-scripts/tree/master/new_methods/bucklin_range

Like ordinary STV, the methods are susceptible to Hylland free 
riding/vote management. This happens because the redistributing 
surpluses step doesn't take into account what votes might contribute to 
electing other candidates/parties later on. But this knowledge may make 
it possible to construct a method that is less susceptible to that kind 
of free riding. Perhaps some kind of lookahead could work, in essence 
vote management DSV. And perhaps it would be easier to apply to a 
Bucklin method like Bucklin-Range or Double Bucklin than to STV since 
the former is more monotone and well-behaved in that regard.