convert Makefile to Xcode project

[shazron]

1. ios-deploy.c needs to have the compiler flag "-x objective-c" to treat it as an Objective-C file.
2. OTHER_LINKER_FLAGS needs to add the MobileDevice private framework and the location of the private framework folder (see Makefile)
3. Turn off ARC
4. Create target for demo.app

This work is in anticipation of the 2.0.0 re-factor, breaking out the commands into their own files and creating a separate libiosdeploy.a. See the 2.0.0 milestone.