iOS 7.1 compatibility

The iPhoneSimulatorRemoteClient framework is gone from the latest version of Xcode. It's been replaced by the 64-bit-only DVTiPhoneSimulatorRemoteClient framework.

This change adds a binary build from the Appcelerator fork of iOS-sim, which has been already been updated to use this framework. It then switches which binary it uses depending on whether or not the iPhoneSimulatorRemoteClient exists.