getextattr/setextattr changes

[manu%netbsd.org@localhost (Emmanuel Dreyfus)]

I plan a few changes to getextattr(1) and setextattr(1) to make them a
bit more usable.

- Add a -s flag to getextattr to specify a vis(3) format. e.g.:
getextattr -s octal user foo file

- Invoke hexdump(1) for displaying the value when getextattr -x is used.
The existing hexadecimal display is just a mess.

- Add a -i flag to setextattr so that the attribute value can be taken
from a file (- for stdin). This would help setting binary values

Opinions?

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu%netbsd.org@localhost