fix issue #242.

Closes #242

See merge request !66

add modified T-junction scenario calibrated via evacuation times which we used for the tgf2019 vadere paper, remove T-junction experiment data (they can be found on our nextcloud).

VadereGui/src/org/vadere/gui/projectview/view/ProjectView.java:
- Also removed unnecessary shortcut "Ctrl + A" to open "ActionShowAboutDialog".
  "Ctrl + A" should be used in the future to select **all** scenario elements in the topography creator.

update TrajectoryMetric-notebook: computation of the velocity, densities and the fundamental diagram. Cutting of trajectories.

Adapted three scenario files for salient behavior (use random seed and spawnAtRandomPositions=true).

Salient behavior

See merge request !68

Used following commands:
- mvn -Dmaven.test.skip=true package
- java -jar VadereSimulator/target/vadere-console.jar migrate -r VadereModelTests/
- git clean -n
- git clean -f (to delete <scenario_file>.scenario.legacy which is created by migration assistant)

# Conflicts:
#	VadereSimulator/src/org/vadere/simulator/projects/io/TrajectoryReader.java