[Pkg-shadow-devel] Bug#1074394: login: move login.defs into new package

[Chris Hofstaedtler]

Package: login

login currently ships /etc/login.defs. Various other packages read
login.defs, without really depending on it.

As a stop-gap, passwd currently Depends: login. The assumption being
that programs needing /etc/login.defs also depend on passwd, because
they probably want useradd/userdel/something-from-passwd.

My plan is to:
- have login in unstable start Providing: login.defs
- other packages can start Depending: login.defs
- update util-linux to Depend: login.defs, making login.defs
  (Pseudo-)Essential. util-linux needs it, because su(1) needs
  /etc/login.defs
- introduce new login.defs package in experimental
- have login.defs take over the /etc/login.defs conffile from login.

Chris