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

hiro/hiro.hpp

@@ -1,3 +1,5 @@
+#pragma once
+
 /* hiro
  * author: byuu
  * license: ISC
@@ -7,9 +9,6 @@
  * it also provides a reference wrapper for terminal applications with optional UIs
  */
 
-#ifndef HIRO_HPP
-#define HIRO_HPP
-
 #include "components.hpp"
 #include "core/core.hpp"
 #include "extension/extension.hpp"
@@ -20,5 +19,3 @@
 #undef DeclareSharedSizable
 #undef DeclareSharedLayout
 #undef DeclareSharedWidget
-
-#endif