Can't save or open a file in iOS devices

[arves100]

iPhone/iPad/iPod devices, according the the GameSpy Open SDK 1.0, doesn't allow using the C function fopen. (The same thing also happens on Android), the Open SDK fixed this isse by using gsifopen, a resonable solution for iDevices while keeping support for the platforms that supports it.

This function MUST be ported into the current SDK to allow iOS devices to fully operate.

[arves100]

Since commit a72f8ac, I have started adding support for the gsifopen function to all the SDK.
This issue will be closed after the porting will be tested.