after searching a file with goto-file and opening a file from goto-files result when
reopened goto-file should display the last query, the according result-set and - if any -
the last highlighted/selected file from the resultset should be highlighted as before.
this way one can open multiple files via goto-file which match the same query without
re-entering the query again and again...
even nicer: open-files result-set should mark files already open in the editor