Implement segmentation by PitchSet.canBeSpelledObjectively

[jsbean]

Create a windowing process with a PitchSet which can be spelled objectively as the last element:

let seq: PitchSetSequence = [[63],[66],[60],[61],[68],[70],[71]]
// => [[63],[66],[60]], [[61],[68],[70],[71]]

[jsbean]

No longer the strategy.