Cross validation folds

[hayesall]

Cross validation folds are missing. They should be retrieved and added, perhaps under respective subfolders.

• webkb
• cora
• citeseer
• imdb
• uwcse

Instances in Boston Housing should be split pretty easily. Keep the main fold for now, but when I work on propositional dataset handling in the future, it could be interesting to provide a case where CV folds can be created for it.

[hayesall]

imdb needs attention.

• starling web page points to female_gender as the target predicate
• walk-er imdb used the worked_under version, and includes the code for generating negative examples
• RRBM-Tensorflow imdb also uses the worked_under version, but uses an alternative style and it's unclear where the negative examples came from.