comment TriangulatePointsBetweenViews function

This TriangulatePointsBetweenViews function have done the fellowing job:
*      1.reconstruction the match pair
*      2.filter out the big reprojection error matches and update the
glob matches_matrix
*      3.save the key point index to the CloudPoint that correspondence
the current 3D point
*      4.And, find out key points in the glob matches_matrix that
correspondence to
*          the current two image key points imges contribute to the 3D
point and save it in the CloudPoint,
*          so that they will not add to the pointcloud twice.