Rewrite many calls to Connect() with Bind()...

... it's the more modern way, and does better type checking, without the
dubious casts of pointers-to-member-functions.

src/tracks/ui/Scrubbing.cpp

@@ -198,9 +198,9 @@ Scrubber::Scrubber(AudacityProject *project)
 
 {
    if (wxTheApp)
-      wxTheApp->Connect
+      wxTheApp->Bind
       (wxEVT_ACTIVATE_APP,
-      wxActivateEventHandler(Scrubber::OnActivateOrDeactivateApp), NULL, this);
+       &Scrubber::OnActivateOrDeactivateApp, this);
    mProject->PushEventHandler(&mForwarder);
 }