call OnInit() from all samples to allow using standard command line options with all of them (patch 1623971)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44354 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/sashtest/sashtest.cpp

@@ -40,6 +40,9 @@ int winNumber = 1;
 // Initialise this in OnInit, not statically
 bool MyApp::OnInit(void)
 {
+  if ( !wxApp::OnInit() )
+    return false;
+
   // Create the main frame window
 
   frame = new MyFrame(NULL, wxID_ANY, _T("Sash Demo"), wxPoint(0, 0), wxSize(500, 400),