Fix bug introduced in rev 1.478 which prevented aliased directories from

being CWD'd (chdir'd) into.
I resisted the temptation to convert ftpalias.cfg to a different (sane)
format (e.g. .ini) at this time, but that really should be done.
Oh, and I noticed that aliases don't work with "DIR" wildcards, so that's a
bug that needs fixing too.