A few minor improvements to the XLS report generator.
A few minor improvements to the XLS report generator.

* In comparison column headers, switched the order of labels, so that
  it's "to" vs "from".

* When a test was present, but not run successfully, put its status in
  the corresponding cell instead of coloring it gray.

opencv/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv