Backported fixes for updating the splash screen and busy info windows

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@19467 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/busyinfo.cpp

@@ -105,9 +105,13 @@ wxBusyInfo::wxBusyInfo(const wxString& message, wxWindow *parent)
 {
     m_InfoFrame = new wxInfoFrame( parent, message);
     m_InfoFrame->Show(TRUE);
+#ifdef __WXMAC__
+    m_InfoFrame->Update();
+#else
     wxYield();
     m_InfoFrame->Refresh();
     wxYield();
+#endif
 }
 
 wxBusyInfo::~wxBusyInfo()