0.5.71: a stronger Hundred Fists, the desktop game updates itself again

The Brawler's Hundred Fists hits much harder: each blow is almost half again as heavy and reaches a little further, so the eight-blow flurry now stands beside the other classes' ultimates. The desktop game now looks for a new version on the login screen even before it reaches the server, so it can no longer get stuck on an old one as 0.5.69 did.