Rename validate to isValid
Remove errorMessage from Graph
Refactor validation
Update comment
Update comment
Remove commented lines
Add toString and name to GraphObject
Change Set to Coollection in constructor
Rename local variables
Add debug messages
Add failing test for cyclic validator
Fixed bug in validator.
Corrected comment.
Merge branch 'master' into fun_with_validators

Conflicts:
	ComputerSystemsSoftwareCore/src/main/java/edu/kpi/pzks/core/model/Graph.java