Add RescorerProvider option to eval methods
Fix NPE when using a rescorer that can be null
Weight iteration convergence estimate towards higher-valued items, since they determine recommendations
Log bad input lines with a message. Only fail if a lot of bad lines are observed.
Fix small logic error in differentiating header file from others
Add more multiple rescorer support
Compress the model.bin file as model.bin.gz. It compresses well in general.