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

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38857 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/imagpcx.cpp

@@ -19,6 +19,7 @@
 
 #ifndef WX_PRECOMP
     #include "wx/object.h"
+    #include "wx/list.h"
     #include "wx/log.h"
     #include "wx/intl.h"
     #include "wx/palette.h"
@@ -29,7 +30,6 @@
 #include "wx/module.h"
 
 #include "wx/hash.h"
-#include "wx/list.h"
 
 //-----------------------------------------------------------------------------
 // wxPCXHandler