Added a few #if wxUSE_XXX

Regrouped image format handlers
  Updated the rest accordingly
  Added changes.txt for wxGTK


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@2795 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/http.cpp

@@ -17,14 +17,15 @@
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
-#pragma hdrstop
+  #pragma hdrstop
+#endif
+
+#ifndef WX_PRECOMP
+  #include "wx/defs.h"
 #endif
 
 #if wxUSE_SOCKETS
 
-#ifndef WX_PRECOMP
-#endif
-
 #include <stdio.h>
 #include <stdlib.h>
 #include "wx/string.h"