dupemerge: merge with waya-zblaxell, fix warning message

dupemerge: merge with waya-zblaxell, fix warning message

Merges up to c92b00c812898fcba6e5ebde14ef83ae597756ee, including
these commits:

	6038ff7 dupemerge: have find tell us the device too
	fd1d958 dupemerge: maybe improve seek performance by sorting perl hashes
	9bf1c63 dupemerge: merge with state-of-the-art on Serenity
	a27ea1f dupemerge: update copyright year to 2010
	593804d dupemerge: sort incumbent inodes too
	1df8571 dupemerge: make inode sort order strictly numeric
	24fecbb dupemerge: make sure 'sort -znr' still considers dev/inode numeric
	c92b00c dupemerge: inodes are now non-numeric