Added error handlings to the methods of following classes or modules -CvPoint2D32f -CvPoint3D32f -CvRect -CvScalar -CvSeq -CvSize -CvSize2D32f -CvSlice -CvSURFParams -CvSURFPoint -CvTermCriteria -CvTwoPoints -CvUtils -CvVideoWriter -GUI -IplConvKernel -IplImage -MouseEvent -OpenCV -Trackbar -Window
Added IplImage#smoothness that returns :smooth, :messy, or :blank. Rake compile will now compile the C extension code.