Remove deprecated MongoDBModel
Add logback dependency
Add mock datasets
Disable debugging output in LynxFactorizer
Fix bug in StopWatch where the timing identifier was printed twice
Fix bug in API where the ID maps were not reset on rebuild

- Also sorted out logging in this commit
Enable build timing and recommendation timing
Chain insertions for each line parsed in DBModel
Switch SQL dialect to H2 in DBModel
Fix bug in DBModel.getNumItems(). Did not group by userField
Make DBModel.setPreference faster by using mergeInto instead of checking for existence
Improve performance of PreprocessorStat by adding two caching helper methods to DBModel
Support threshold for numeric classifiers by using distance to closest integer
Reconfigure timing measures in Evaluator
Add threshold parameter on ANN evaluation
Simplify evaluation of KNN
Add timing class to evaluate the preprocessor performance on a large synthesized dataset