Constraint Validator Mock

Extended architecture to include readers for data.
Outlined constraint validator.
Graph Class
Tests for Graph
Validator Interface for JSONArray
toString for Data
PathValidator

Class for validation of a single path. Needed for Validation of Kuratowski Subdivisions.
ConstraintValidator

Final steps towards implementing the ConstraintValidator.
Merge pull request #1 from TiloW/ConstraintValidator

Constraint validator