chroot specify dir to chroot to for GUEST and CHROOT users, to
override -a anondir or the user's homedir.
homedir specify dir to change to upon login; also used for ~ expansion
and $HOME for subprocesses)
both of these can take % escapes: %u (username), %d (homedir), %c (class).
* fix NLST to take a pathname not a STRING, so that ~ expansion works
* modify CWD to use the homedir parsed from curclass.homedir
* implement format_path(dst, src), to parse src expanding % escapes (see above)
into dst.
* rename format_file() to display_file()
e3a2c5cc44