minMaxLoc() and minMaxIdx()

I felt something is a little off about `cv.minMaxLoc()`.

> http://docs.opencv.org/modules/core/doc/operations_on_arrays.html?highlight=minmaxloc#minmaxloc
> Python: cv2.minMaxLoc(src[, mask]) → minVal, maxVal, minLoc, maxLoc
> C: void cvMinMaxLoc(const CvArr* arr, double* min_val, double* max_val, CvPoint* min_loc=NULL, CvPoint* max_loc=NULL, const CvArr* mask=NULL )

So I thought about how I wish I could write (src, minVal, maxVal, minLoc, maxLoc, mask) style args like Python.
And `minMaxIdx()` can be substituted for `minMaxLoc(src, minVal, maxVal, minIdx, maxIdx)`.

Please consider it.