programs require that the mode is 4550 so that execution of the
setuid program can be restricted to members of a group.
* setuid-wrappers: remove a race condition in the creation of the
wrappers if the ownership or mode was different than root:root and
4555.
* setuid-wrappers: allow the full path of the wrapped program to be
specified, rather than looking it up in $PATH.
svn path=/nixos/trunk/; revision=16733
dba1964122