return value indicate success.
(get_response): check NULL from fgets
(edit_time, edit_attributes): new functions for reading values and
offering list of answers on '?'
(edit_entry): use edit_time and edit_attributes
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@4216 ec53bebd-3082-4978-b11e-865c3cabbd6b