dupemerge: have find tell us the device too

dupemerge: have find tell us the device too

faster-dupemerge cannot be used to link files on multiple filesystems
because the hardlinks will fail; however, if this is attempted anyway
then files with identical weak keys (size+timestamp+permissions) and
identical inode numbers might be considered as identical for hashing
and comparing purposes when they are not.  That would be bad.