Fix a clang warning with GHC / Haskell Platform on Mac OS X 10.9

If you’re using GHC on Mac OS X 10.9 Mavericks with the ghc-clang-wrapper your terminal is probably spamming you with

warning: control reaches end of non-void function [-Wreturn-type]

Thankfully this is easy to fix, just edit /usr/bin/ghc-clang-wrapper and change line 30 from:

extraClangArgs="-Wno-invalid-pp-token -Wno-unicode -Wno-trigraphs"

to:

extraClangArgs="-Wno-invalid-pp-token -Wno-unicode -Wno-trigraphs -Wno-return-type"

Presumably this will be incorporated upstream eventually but for now this will take care of it.

-viewDidUnload deprecated, and not safe anyway

You may have been doing something like this in your iOS apps:

- (void)viewDidLoad {
    [super viewDidLoad];
    [UAStoreFront registerObserver:self];
}
    
- (void)viewDidUnload {
    [super viewDidUnload];
    [UAStoreFront unregisterObserver:self];
}

This will cause a hard to diagnose crash in some circumstances. Despite the symmetry in names, these are not called in pairs. -viewDidUnload is only called in low memory situations prior to iOS 6, and is never called in iOS 6 anymore. You should be doing this in -viewWillAppear and -viewWillDisappear, or in -init and -dealloc. If you had other things being done in -viewDidUnload you should move them to -dealloc.