I am removing these from the source code in preparation for an
upcoming 1.9.18alpha release. We can't release with this code in there
as it currently stands as it might breach ITAR export restrictions in
the US.
I've discussed ways around this with Jeremy and we can put the code
back in with appropriate modifications once it is needed.
Note that this code isn't actually used in Samba yet, so removing it
has no effect.
If anyone wants the code then look in ~samba-bugs/arcfour/ or grab it
from the CVS attic.