Improved harvester behaviour, reworked the job register system and added auto roadbuilding.

Math.js

@@ -0,0 +1,7 @@
+module.exports = {
+    clamp: function(v, min, max){
+        if(v<min) v = min;
+        else if (max < v) v = max;
+        return v;
+    } 
+}