Add check for wxUSE_DRAG_AND_DROP dependency on wxUSE_OLE

Library itself can be built successfully when wxUSE_DRAG_AND_DROP==1 and
wxUSE_OLE==0 but several wxDropTarget functions (referred in wxWindowMSW,
wxTextDropTarget, wxFileDropTarget) are reported as missing during linking
the application.

include/wx/msw/chkconf.h

@@ -363,6 +363,15 @@
 #           define wxUSE_OLE_AUTOMATION 0
 #       endif
 #   endif
+
+#   if wxUSE_DRAG_AND_DROP
+#       ifdef wxABORT_ON_CONFIG_ERROR
+#           error "wxUSE_DRAG_AND_DROP requires wxUSE_OLE"
+#       else
+#           undef wxUSE_DRAG_AND_DROP
+#           define wxUSE_DRAG_AND_DROP 0
+#       endif
+#   endif
 #endif /* !wxUSE_OLE */
 
 #if !wxUSE_ACTIVEX

include/wx/msw/setup0.h

@@ -1374,7 +1374,7 @@
 
 // Use wxDropTarget and wxDropSource classes for drag and drop (this is
 // different from "built in" drag and drop in wxTreeCtrl which is always
-// available). Requires wxUSE_DATAOBJ.
+// available). Requires wxUSE_DATAOBJ and wxUSE_OLE.
 //
 // Default is 1.
 //