https://github.com/Aegisub/Aegisub/commit/dd67db47cb22

--- src/utils.cpp.orig	2014-12-08 00:07:09 UTC
+++ src/utils.cpp
@@ -44,6 +44,7 @@
 #include <boost/filesystem/path.hpp>
 #include <map>
 #include <unicode/locid.h>
+#include <unicode/unistr.h>
 #include <wx/clipbrd.h>
 #include <wx/filedlg.h>
 #include <wx/stdpaths.h>