Small changes, also touched by Xcode 5

* Fixed error discovered in Xcode 5 (using `NSArray` instead of `NSSet` for a local variable)
* Reimplemented `SMInputStream.m`’s `-dealloc` to release the `readQueue`, guarded by `CHECK_FOR_GCD`
* `formatNoteNumberWithBaseOctave` returns `NSString`s with nice unicode sharp symbol ‘♯’, rather than a standard ‘#’
* Added OS X static library target
* Project file updated based on Xcode 5’s recommendations

Sorry I haven’t split this up into smaller pull requests.