JS for IE8: even more JS fixes

refs #6417
JS/cleanup: start to clean up response handling

First step: get rid of the messy workaround for the problem that
notifications got lost once the whole body is re-rendered. This
should be solved either on server side or by detaching and re-
attaching existing notifications in such scenario.
JS/cleanup: separate redirect header handling
IE8/JS: some more console logging fixes

refs #6417