Defaulted sim launch to --retina and --tall

Hi there, this pr defaults launching the sim to make use of --retina and --tall. Without these options, the sim will always come up in 3.5-inch mode. As the iPhone4 os almost a distant memory now for for iOS devices, it strikes me that defaulting to retina tall (ie 4-inch) is the right way to go. Hope this helps, happy to make any improvements or changes necessary if you think there's a better way to solve this problem.