libmisc/pam_pass_non_interractive.c, libmisc/Makefile.am: Renamed.
* libmisc/pam_pass_non_interractive.c, lib/prototypes.h:
non_interactive_password and non_interactive_pam_conv do not need
to be externally visible.
* libmisc/pam_pass_non_interractive.c: Added declaration of
ni_conv.
* libmisc/pam_pass_non_interractive.c: Only compile ifdef USE_PAM.
* libmisc/pam_pass_non_interractive.c, lib/prototypes.h:
Added do_pam_passwd_non_interractive().
* src/chpasswd.c: Use do_pam_passwd_non_interractive().
