Add temporary demo function for head changes
Mockup diff response in review service
Add a diff button in depTree if needed and ...

Pass on wrong tokens if something is wrong
Add a compare button in review template
Use a more clever token colorization

Check the comment, it can now be customized if need be.
Rename toggleDiff button in depTree template
Add optional diff functionality to depTree service
Allow custom styling for dependencyTree directive
Properly reset edge styling in dependencyTree
Refactor in dependencyTree