Issue 7 Provide ability to determine file dependencies
Removed passing Model to the dependency processor.
Added Dependency class implementation.
Added dependency-related methods to the Model interface and implementation.
Added dependency processor to model type.
Moved dependency-related classes to the new "extensions" package.
Made dependencies node type extend nt:unstructured.
Merge pull request #101 from elvisisking/dep-processor

Issue 7 Provide ability to determine file dependencies