Include wx/hash.h according to precompiled headers of wx/wx.h (with other minor cleaning).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38868 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/fontutil.cpp

@@ -27,12 +27,12 @@
 #ifndef WX_PRECOMP
     #include "wx/font.h" // wxFont enums
     #include "wx/encinfo.h"
+    #include "wx/hash.h"
 #endif // PCH
 
 #include "wx/fontutil.h"
 #include "wx/fontmap.h"
 #include "wx/tokenzr.h"
-#include "wx/hash.h"
 #include "wx/module.h"
 
 #if wxUSE_PANGO