* display the median time instead of the average.
* add a "Reliability" column (sum up the metrics and the checker results).
* the "selected language", "SafeSearch", "Time range" values are displayed as "broken" when the checker tests fail.
AJAX requests send the X-Requested-With HTTP header,
so searx.webapp.autocompleter returns the results with the expected data format.
Related to #2127Close#2203