user can group options and control a group's waps by a single slider

[mensch72]

grouping/ungrouping should be possible via the poll's or option's context menu and is purely participant-specific, allowing the participant to more effectively control waps of several options at once.

a group is sorted where the best-ranked member would appear. it can be expanded to show its members' sliders.

the group wap slider controls the median wap, shifting it preserves the members' differences in logit-transformed waps.

later, one might even form hierarchies of subgroups