Since it's just a state-toogler, use the return value of the
method to set the values directly.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

They were causing variable scoping conflicts. This in turn caused the
widget to not update. Active property is not needed since the handling
of active/inactive vehicle is handled outside of the control

Allows for signal count > 1

Also merged MissionController and MissionEditorController into single
MissionController implementation