Do our best to show messages logged during program startup/shutdown.

Do our best to show messages logged during program startup/shutdown.

Use wxMessageOutputBest to show them even under Windows where programs usually don't have stderr at all and also don't disable log target auto-creation during shutdown as it's arguably better to leak memory (which shouldn't matter much when the program is about to exit anyhow) than to not show possibly important messages.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61450 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775