Fixed yaw error normalization issue

lib/Controller.js

@@ -299,8 +299,8 @@ Controller.prototype._control = function(d) {
       ;
 
     // Normalize eyaw within [-180, 180]
-    while(eyaw <  Math.PI/2) eyaw += Math.PI;
+    while(eyaw < -Math.PI) eyaw += (2 * Math.PI);
-    while(eyaw >= Math.PI/2) eyaw -= Math.PI;
+    while(eyaw >  Math.PI) eyaw -= (2 * Math.PI);
 
     // Check if we are within the target area
     if ((Math.abs(ex) < EPS_LIN) && (Math.abs(ey) < EPS_LIN) && (Math.abs(ez) < EPS_ALT) && (Math.abs(eyaw) < EPS_ANG)) {