Addapted Weka FOS Manager to support exporting/importing of binary RandomForest and FastRandomForest classifiers to/from PMML.

Summary: Adapted to the latest changes to the FOS API and added support for consuming/producing PMML.

Test Plan: Added; Updated existing.

Reviewers: deag, diogo.ferreira, antonio.alegria, miguel.duarte

Reviewed By: deag