Test are refactored. Remove compilation test, aggregate ast tests.
Work on #18. Refactoring AST comparator. Improve configuration possibilities.
Work on #18. Refactoring AST comparator. Remove unnecessary comparisons.
Work on #18. Refactoring AST comparator. Remove duplicate configuration entry.
Work on #18. Refactoring AST builder. Added Javadoc.
Close #18. Refactoring.