add missing license header

source/ArmarXGui/applications/ArmarXGui/ArmarXMainWindow.cpp

source/ArmarXGui/applications/ArmarXGui/ArmarXMainWindow.h

...s/ConditionViewerPlugin/widgets/ConditionViewerWidget.cpp

...ins/ConditionViewerPlugin/widgets/ConditionViewerWidget.h

...ugins/ObserverPropertiesPlugin/widgets/ObserverWidget.cpp

...plugins/ObserverPropertiesPlugin/widgets/ObserverWidget.h

...gui-plugins/ScenarioManager/executor/ApplicationStarter.h

...rXGui/gui-plugins/ScenarioManager/executor/StopStrategy.h

...rmarXGui/gui-plugins/ScenarioManager/gui/OptionalEdit.cpp

.../ArmarXGui/gui-plugins/ScenarioManager/gui/OptionalEdit.h

...i-plugins/ScenarioManager/gui/OptionalPropertyFactory.cpp

...gui-plugins/ScenarioManager/gui/OptionalPropertyFactory.h

...i-plugins/ScenarioManager/gui/OptionalPropertyManager.cpp

...gui-plugins/ScenarioManager/gui/OptionalPropertyManager.h

...e/ArmarXGui/gui-plugins/ScenarioManager/gui/treemodel.cpp

source/ArmarXGui/gui-plugins/ScenarioManager/gui/treemodel.h

...marXGui/gui-plugins/ScenarioManager/parser/PidManager.cpp

...ArmarXGui/gui-plugins/ScenarioManager/parser/PidManager.h

...rXGui/gui-plugins/ScenarioManager/test/ControllerTest.cpp

...ui/gui-plugins/ScenarioManager/test/DataStructureTest.cpp