added wifi per-floor optimization

added plot to wifi-quality-analyzer
changes to per-floor wifi models
minor fixes

geo/BBox3.h

@@ -89,11 +89,14 @@ public:
 		p2 += p;	// increase maximum
 	}
 
-		/** set both, min/max z to the same value */
-		void setZ(const float z) {
-			p1.z = z;
-			p2.z = z;
-		}
+	/** set both, min/max z to the same value */
+	void setZ(const float z) {
+		p1.z = z;
+		p2.z = z;
+	}
+
+	void setMinZ(const float z) {this->p1.z = z;}
+	void setMaxZ(const float z) {this->p2.z = z;}
 
 	/** does the bbox contain the given point? */
 	bool contains(const Point3& p) const {