moved ParentAwareNode to model package, in order to consolidate all things Node
renamed Node to SimpleNode
introduced trait Node as common super trait for all Nodes
added addNode method to Graph
uses addNode in Analyzer
use addNode in GraphSliceTest
GraphTest now uses addNode
removed final usages of add
introduced method connectNodes
switched to usage of connectNodes
converted to usage of connectNodes
converted to usage of connectNodes
connect replaced by connectNodes
completely replaced old connect method
renamed connectNodes to connect
renamed addNodes to add after inlining the original add
changed argument types of addEdge to Node
changed filter type to Node => Boolean
changed edge filter argument to work on Nodes
Categorizer/Slicer now return Nodes

compiles ... 3 Test failures to fix