CHANGES:
- Factored out computing marginals from computing inside and outside representations.
- Added a function to compute the max-margin objective over given trees.
- Output max as well as argmax of loss-augmented tree score. This is used for computing the max-margin objective.
- Added a function to compute the score of a tree. This is used for computing the max-margin objective.
- (BUG FIX) Set spans when we apply transformations to a tree (Binarize, AddRootNode, ExpandUnaryProductions).