[TIMOB-15116]iOS: Adding support for 64 bit iOS7 4-inch simulator.

[srahim]

TESTING INSTRUCTIONS
Code Review of the ios-sim project to be done on https://github.com/appcelerator/ios-sim/pull/5

the testing can be done only through CLI.

• Go to any Titanium app folder in terminal or create a new app.
• "ti build -p ios -Y iphone -S 7.0 --retina --tall --sim-64bit"
• Kill the ios simulator app.
• Test out variation of the --retina, --tall and simulator versions and sim types for regression testing.

Make sure to kill the simulator before running the next command. Otherwise the right simulator will not be displayed

[vishalduggal]

CR and FR ok. Able to launch 64 bit and non 64 bit sim on iOS7. 64 bit sim parameter ignored on lower versions. APPROVED