Refactored the addModel code to remove code duplication.
Refactor manager to avoid keeping the model in memory.

Conflicts:
	src/main/java/com/feedzai/fos/impl/weka/WekaManager.java
	src/main/java/com/feedzai/fos/impl/weka/utils/WekaThreadSafeScorerPool.java
Close WekaManager ports on scorer tests.
Improved classifier loading performance.

The loading from disk was not being buffered. Added a BufferedInputStream with a decent block size to improve the speed of load.