there is a PHP function number_format which does the trick. So, to make stats (the "Stats" block) looks like this: "total plays: 123,123,123" you should edit the code of the STATS block:
current code (one of the lines, changes in other lines are the same):
"STAT-PLAYSTOTAL" => $res["total"],
new code:
"STAT-PLAYSTOTAL" => number_format($res["total"]),