updated todo
added a test for failure messages ... needs matching implementation
added a ConstraintViolation task with a specific toString implementation, to be used in reporting test failures.
refactored everything to use ConstraintViolations
added tests
fixed a bunch of tests
fixed another test
created fxml only for SceneBuilder, rename NodeViewTemplate to NodeView
refactored the last batch of test towards use of ConstraintViolations
constraint violations now produce proper error messages
moved main to testclass
changed mainView to scrollable View
Merge branch 'master' of https://github.com/schauder/degraph.git