in browser_refresh() and titlebar(), don't display overly long filenames

in browser_refresh() and titlebar(), don't display overly long filenames
with ellipses if the number of columns is extremely small; also, in
certain places, call wnoutrefresh(bottomwin) after calling
blank_statusbar(), in order to ensure that the statusbar is actually
blanked

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@3751 35c25a1d-7b9e-4130-9fde-d3aeb78583b8