add Tracker and MultiTracker python bindings

modules/tracking/samples/tracker.py

@@ -0,0 +1,30 @@
+import numpy as np
+import cv2
+
+cv2.namedWindow("tracking")
+camera = cv2.VideoCapture("E:/code/opencv/samples/data/768x576.avi")
+bbox = (638.0,230.0,56.0,101.0)
+tracker = cv2.Tracker_create("MIL")
+init_once = False
+
+while camera.isOpened():
+    ok, image=camera.read()
+    if not ok:
+        print 'no image read'
+        break
+
+    if not init_once:
+        ok = tracker.init(image, bbox)
+        init_once = True
+
+    ok, newbox = tracker.update(image)
+    print ok, newbox
+
+    if ok:
+        p1 = (int(newbox[0]), int(newbox[1]))
+        p2 = (int(newbox[0] + newbox[2]), int(newbox[1] + newbox[3]))
+        cv2.rectangle(image, p1, p2, (200,0,0))
+
+    cv2.imshow("tracking", image)
+    k = cv2.waitKey(1) & 0xff
+    if k == 27 : break # esc pressed