Fix invalid use of wxSizer flags in samples and utils.

Remove alignment flags that result in asserts because of being used in
combinations that don't make sense.

Also use wxSizerFlags in the lines that were changed.

utils/screenshotgen/src/guiframe.h

@@ -119,6 +119,8 @@ private:
     void AddPanel_3();
     void AddPanel_4();
     void AddPanel_5();
+
+    wxSizerFlags m_commonExpandFlags;
 };
 
 #endif //_GUIFRAME_H_