Convert all remaining File stuff to Path; single DistConfig instead of two classes.

DistConfig also wraps a Config instances and handles the logic required for selecting which properties should come from which files. Also, ConfigLoader is not extended anymore.
Throw IOException in list, consistent with other FileLike impls
Set kryoserializer buffer to 100mb
Add support for parallel extraction of multiple languages
Merge pull request #26 from dbpedia/milestone3

Completes milestone 3: Single united DistConfig class instead of two; Support for parallel multiple language extraction