broken test in SIFT... resolved

maychSIFTKeyPoints (function and tests) broke in OpenCV 2.3.1

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##### ERROR: SimpleCV.tests.tests.test_matchSIFTKeyPoints

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     Traceback (most recent call last):
      File "/usr/local/lib/python2.7/dist-packages/nose-1.1.2-py2.7.egg/nose/case.py", line 197, in runTest
        self.test(*self.arg)
      File "/home/kscottz/SimpleCV/SimpleCV/tests/tests.py", line 3102, in test_matchSIFTKeyPoints
        skp, tkp =  img.matchSIFTKeyPoints(img)
      File "/home/kscottz/SimpleCV/SimpleCV/ImageClass.py", line 12109, in matchSIFTKeyPoints
        detector = cv2.FeatureDetector_create("SIFT")
    AttributeError: 'module' object has no attribute 'FeatureDetector_create'