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/common/image.cpp

@@ -19,6 +19,7 @@
 #ifndef WX_PRECOMP
     #include "wx/log.h"
     #include "wx/app.h"
+    #include "wx/hash.h"
 #endif
 
 #include "wx/image.h"
@@ -28,12 +29,11 @@
 #include "wx/wfstream.h"
 #include "wx/intl.h"
 #include "wx/module.h"
-#include "wx/hash.h"
 #include "wx/utils.h"
 #include "wx/math.h"
 
 #if wxUSE_XPM
-#include "wx/xpmdecod.h"
+    #include "wx/xpmdecod.h"
 #endif
 
 // For memcpy