Resolve "Problem::getState(structure) doesn't care about structure"

Closes #343 (closed)

include/core/processor/is_motion.h

@@ -26,8 +26,8 @@ class IsMotion
 
         // Queries to the processor:
         virtual TimeStamp       getTimeStamp() const = 0;
-        virtual VectorComposite getState() const = 0;
-        virtual VectorComposite getState(const TimeStamp& _ts) const = 0;
+        virtual VectorComposite getState(const StateStructure& _structure = "") const = 0;
+        virtual VectorComposite getState(const TimeStamp& _ts, const StateStructure& _structure = "") const = 0;
 
         std::string getStateStructure(){return state_structure_;};
         void setStateStructure(std::string _state_structure){state_structure_ = _state_structure;};