Revert "Remove dynamic loading of SetThreadUILanguage."

This reverts commit c5ce5bf168.

Using SetThreadUILanguage() directly results in compilation errors with MSVC 8,
see e.g.

http://buildbot.tt-solutions.com/wx/builders/wxMSW-VC8-full/builds/129/steps/libraries/logs/stdio

so keep loading it dynamically for now.

See https://github.com/wxWidgets/wxWidgets/pull/112

src/common/intl.cpp

@@ -473,7 +473,12 @@ bool wxLocale::Init(int language, int flags)
             // behavior, so avoid calling it there.
             if ( wxGetWinVersion() >= wxWinVersion_Vista )
             {
-                ::SetThreadUILanguage(LANGIDFROMLCID(lcid));
+                wxLoadedDLL dllKernel32(wxS("kernel32.dll"));
+                typedef LANGID(WINAPI *SetThreadUILanguage_t)(LANGID);
+                SetThreadUILanguage_t pfnSetThreadUILanguage = NULL;
+                wxDL_INIT_FUNC(pfn, SetThreadUILanguage, dllKernel32);
+                if (pfnSetThreadUILanguage)
+                    pfnSetThreadUILanguage(LANGIDFROMLCID(lcid));
             }
 
             // and also call setlocale() to change locale used by the CRT