Fixed some compiler warnings in Xcode

There are still a couple warnings that need to be squashed and I'm not sure how to fix:

Scene_ScriptBinding.h line 1988: Unsequenced modification and access to 'nextArg'

```cpp
if ( worldGroundAnchorAElementCount == 1 && argc > 5 )
    {
        worldGroundAnchorA.Set( dAtof(argv[nextArg]), dAtof(argv[nextArg++]) );
        nextArg += 2;
    }
```

PBXCp Warning: skipping copy phase strip, binary code is signed: for libLeap.dylib