1. some more of "#if wxUSE_XXX" here and there

2. Makefile fixes for Cygwin compilation


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@2773 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/layout.cpp

@@ -16,6 +16,7 @@
 // ----------------------------------------------------------------------------
 // headers
 // ----------------------------------------------------------------------------
+
 #ifdef __GNUG__
     #pragma implementation "layout.h"
 #endif
@@ -29,6 +30,8 @@
 
 #include "wx/defs.h"
 
+#if wxUSE_CONSTRAINTS
+
 #ifndef WX_PRECOMP
     #include "wx/window.h"
     #include "wx/utils.h"
@@ -1762,3 +1765,4 @@ wxSpacingSizer::~wxSpacingSizer()
 {
 }
 
+#endif // wxUSE_CONSTRAINTS