Backport Mac OS X build fix

include/platform/wxwidgets/scrollbar.hpp

@@ -2,6 +2,7 @@
 #define _scrollbar__hpp__defined__
 
 #include <wx/scrolbar.h>
+#include <functional>
 
 class scroll_bar : public wxScrollBar
 {

src/platform/wxwidgets/textrender.cpp

@@ -3,6 +3,7 @@
 #include "library/utf8.hpp"
 #include <wx/dc.h>
 #include <wx/dcclient.h>
+#include <wx/image.h>
 
 extern const uint32_t text_framebuffer::element::white = 0xFFFFFF;
 extern const uint32_t text_framebuffer::element::black = 0x000000;