Added samples/dll for showing how to use wxWidgets to implement

a DLL that is used from another application written with a different
toolkit (or different wx version).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62784 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

configure.in

@@ -7564,7 +7564,7 @@ if test "$wxUSE_GUI" = "yes"; then
     if test "$TOOLKIT" = "MSW"; then
         SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS regtest"
         if test "$wxUSE_UNIVERSAL" != "yes"; then
-            SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS ownerdrw nativdlg"
+            SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS ownerdrw nativdlg dll"
         fi
     fi
     if test "$TOOLKIT" = "PM" -a "$wxUSE_UNIVERSAL" != "yes"; then