Update to 20160106 OS X Preview for Developers release.

byuu says:

New update. Most of the work today went into eliminating hiro::Image
from all objects in all ports, replacing with nall::image. That took an
eternity.

Changelog:
- fixed crashing bug when loading games [thanks endrift!!]
- toggling "show status bar" option adjusts window geometry (not
  supposed to recenter the window, though)
- button sizes improved; icon-only button icons no longer being cut off

nall/string/core.hpp

@@ -1,4 +1,4 @@
-#ifdef NALL_STRING_INTERNAL_HPP
+#pragma once
 
 //only allocators may access _data or modify _size and _capacity
 //all other functions must use data(), size(), capacity()
@@ -54,5 +54,3 @@ auto string::length() const -> uint {
 }
 
 }
-
-#endif