changing the passwords with PAM.
* src/newusers.c: Split the usage string in smaller parts to
allow enabling single parts.
* man/newusers.8.xml: Indicate the options and configuration
variables valid for PAM and non-PAM versions.
* man/newusers.8.xml: Added pointer to /etc/pam.d/chpasswd.
enable/disable the usage of PAM to authenticate the callers of
account management tools: chage, chgpasswd, chpasswd, groupadd,
groupdel, groupmod, useradd, userdel, usermod.
* src/Makefile.am: Do not link the above tools with libpam if
account-tools-setuid is disabled.
* src/userdel.c, src/newusers.c, src/chpasswd.c, src/usermod.c,
src/groupdel.c, src/chgpasswd.c, src/useradd.c, src/groupmod.c,
src/groupadd.c, src/chage.c: Implement ACCT_TOOLS_SETUID
(--enable-account-tools-setuid).
* etc/pam.d/Makefile.am: Install the pam service file for the
above tools only when needed.
* src/useradd.c, src/userdel.c, src/usermod.c: It is no more
needed to initialize retval to PAM_SUCCESS.
skey and md libraries...
* src/Makefile.am: ...Specify for each binary which library is
required. skey and md are required for the binaries with
authentication of the user (chfn, chsh, login, passwd, su). intl
is required for all. mcrypt is required for user (chfn, chsh,
login, passwd, su, sulogin) and group (newgrp, gpasswd)
authentication and for the creation of passwords (chpasswd,
chgpasswd, gpasswd, newusers, passwd).
