Updated to iOS 7.1 and latest ios-sim

I updated the CMake file to point to the latest iOS SDK (7.1). Additionally, ios-sim didn't work with the latest SDK anymore as it is linked against an older version of the simulator framework. I forked phonegap/ios-sim, added in the unbuffered option so sysouts are immediately visible in the console. I send a [PR to upstream](https://github.com/phonegap/ios-sim/pull/76) instead of your fork. If you want i can update your fork to the upstream version and send a PR.

I tested this only on the CLI (IOSDemo app).