M-H proposal: shift several transitions at once
shift left or right
swap backup
m-h init shift
M-H proposal: move transition by more than 1 frame at once
CheatingAligner - share cache with ViterbiAligner
NodeTimeline: data structure better suited to shifting transitions
TransitionRefinery.train()
StateTimeline
StateTimeline segments
StateTimeline transition manipulation
StateTimeline concatenation (restores M-H)

Plus some extra documentation.
removed StatePath
ModelTrainer refactoring
SpeakerDepModelTrainer
BinarySegmentation: negate, intersect
extra silence trainer
simplified StatePool
don't add silence by default
better naming (Alignment -> OldAlignment; StateTimeline -> Alignment)