In sync_chroot(), this makes the messages be a bit more precise with
exactly which thing they are syncing where.  This is based on my users
expressing confusion at what is going on (especially when something is
taking a long time, and they have to blame something for blocking).
With these changes, I haven't gotten such confusion in a long time
(but maybe my users just got used to it).

In delete_chroot(), this changes "temporary copy" to "chroot copy",
since in Parabola's version of the tools, the function can get called
from other places, and it isn't necessarily operating on a temporary
copy.