Moving EA function to libutil

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

Hello

I seems desirable to move extended attribute copying functions from libc
to libutil. This is about
extattr_copy_file
extattr_copy_fd
extattr_copy_link
cpxattr
fcpxattr
lcpxatte

While there, it seems it would be desirable to move
extattr_namespace_to_string
extattr_string_to_namespace

Removing functions from libc rquire bumping the major, which seems
highly undesirable. 

- does the rule apply between releases? I just added EA copying
functions to libc, can I move them to libutil without bumping the major?

- does the rule apply to unused stuff? EA support has been completely
broken for years, I resurected it a few weeks ago. I am sure nobody was
using it (kernel did not built, and with the build fixes it had a few
lock-related panics). OTOH at least src/usr.sbin/extattrctl and
src/usr.bin/extattr did link with extattr_namespace_to_string and
extattr_string_to_namespace until now, but nobody has been using that
two commands.

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