fixed two bugs in ActivityButterPressure:

1) when barometer produces false measurements, we needed some kind of upper boundary
2) coding error static.. while initializing this object over multiple test iterations isnt the best idea

grid/walk/v2/modules/WalkModuleHeadingVonMises.h

@@ -48,6 +48,7 @@ public:
         if (startNode.getType() == GridNode::TYPE_STAIR) {var *= 3;}
 
         // adjust the state's heading using the control-data
+        //TODO: if motionaxis detects landscaping, do not do this!
         state.heading.direction += ctrl->turnSinceLastTransition_rad + var;
 
         //set kappa of mises