Made wxBufferedOutputStream call Sync() in the destructor and SeekO(). Documented this. Use buffered streams in wxImage. Seems to significantly speed-up the sample. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@4847 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775