Changes in OpenFlispPerspectives for java 1.6 compability
Added model for a set of components, Circuit, and basic testing.
Merge pull request #6 from cthsvedani/master

Changes in OpenFlispPerspectives for java 1.6 compability
Fixed possible NPE while setting non-existent output.
Makes Output forward changes to its connections.
JavaDoc updated.
Merge branch 'master' of github.com:ehannes/OpenFlisp into ehannes-master
Minor fixes before merge.
Merge branch 'master' of github.com:DAT055-2/OpenFlisp
Added a signal collection helper.
Fixed that connections should correctly update its common state.
Removed exception from component evaluation and made toString more readable.
Added a gate with a constant output state.
Added method to get all source components from a circuit.
Added circuit simulation.
Added a identifier for the context of a logic event listener.
Refactored ComponentEventDelegator and added support for ListenerContext.
Added unit test for SignalCollection.
Added ComponentAdapter when not listening to all events.
Changed ComponentListener to ComponentAdapter for the simulation listeners.