cp/mv and extended attributes preservation

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

Currently, our cp(1) will never preserve extended attributes, and mv(1)
will only do so across the same filesystem (that is, when it can use
rename(2)). While I found no specification that it should be done, it
seems Linux and Darwin do that. 

Any objection to modify cp(1) and mv(1) to preserve extended attributes?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost