Neat white vinegar is great for places like car showrooms where they get car wax on the glass or for cafe windows where grease is a problem. Better still, go to a place that sells bio diesel and buy ascetic acid. Dilute it 20 to 1 and don't ever sniff it. It'll clean god knows what off glass and not damage UPV frames.
As for the white stains, maybe they're in between the glass if it's a double glazed unit which has 'blown'.
Apart from that, patio cleaner gets limescale off glass like nothing on this earth. Apply with a mop or sprayer, wait 10 seconds and hose down with plenty of water. Any spillage on the ground will notice so be carefull.