This allows users to edit password files using temporary files created
in /dev/shm. This commit also tidies other things up and fixes minor
bugs and griviences that should be separate commits but aren't.

Reported-by: rupa <rupa@lrrr.us>

this allows completing password entries without explicitly typing 'show'

The default permissions set by 'install' are 0755 which is not
what we want for manpages and the bash completion file.

It's meant to be source, so no need for it to start with #!/bin/bash
rpmlint complains about this.

This commit introduces these variables, and defaults to using
the same values as the ones that were used before. The advantage
of doing this is to make it easier to use some distro-specific
layout. When this is desirable, these variables can be overridden
to what is appropriate at package build time.

Reported-by: Theo Belaire <tbelaire@uwaterloo.ca>

Add a --no-echo flag to the insert operation so that the password isn't
echoed when entering it. This requires the user to echo the password
twice for confirmation.

Reported-by: Dominic Lüchinger <d.luechinger@snowgarden.ch>

This also prevents showing the second <word> of the password in the
prompt.