remduced usage of configuration in ConstraintBuilder
first test of failure message

Tested the negativeFailureMessage
change Dataprovider to singleton
clean up: delete unused class
using JavaGraph for local test
changed controller implementation to ownfxml File
Delete old nodecontroller and view
rename ownController to nodeController
clean old comments
added Chess Testdata
access to nodes over Dataprovider
iterate over nodes for viewing it
showing all topNodes
added mouse click for every node
Merge branch 'master' of https://github.com/schauder/degraph.git