Block in wxMSW wxProgressDialog::Update(max) until the dialog is dismissed.

For consistency with the generic version and because it makes more sense than
blocking in the dialog destructor (which is the only other alternative for the
dialogs without wxPD_AUTO_HIDE to work), we should block in Update() when the
maximal value is reached for dialogs without wxPD_AUTO_HIDE style until the
dialog is dismissed.

Document this behaviour even more clearly.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65507 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/progdlgg.h

@@ -62,7 +62,8 @@ public:
         Uncancelable = -1,   // dialog can't be canceled
         Canceled,            // can be cancelled and, in fact, was
         Continue,            // can be cancelled but wasn't
-        Finished             // finished, waiting to be removed from screen
+        Finished,            // finished, waiting to be removed from screen
+        Dismissed            // was closed by user after finishing
     };
 
 protected: