* IReachablePointProvider to get points to place pedestrians (overlap with other pedestrians must be checked)
* GUI to add random pedestrians
* TreeView showing all ScenarioElements in the TopographyCreator.

TraCI and Cache handling update

See merge request !91

If the getTargetId TraCI-Command is executed with the targetId "-1" (invalid for any agent) then the command returns a list of all targetIds currently in the simulation.

This reverts commit 35976b6f.

# Conflicts:
#	Scenarios/ModelTests/TestPsychology/CognitionAndBehavior/scenarios/12-CounterFlow-SBEnabled.scenario

Removed "VShape.copy()", renamed "AttributesAgentPsychology" to "PsychologyStatus" and updated migration ""

This allows to calculate the hash value of a given scenario to find
the correct cache version.

Bugfix in "TargetChangerController": "useStaticTargetForAgent()" did not update agent's "nextTargetListIndex" properly

Renamed:
- "targetOrientationAngleThreshold" to "walkingDirectionSameIfAngleLessOrEqual"
- "angleCalculationType" to "walkingDirectionCalculation"

Also:
- Extended unit test "OSMBehaviorControllerTest".
- Implemented migration "TargetVersionV1_6" to reflect this renaming.