Bug 17379: Add a man page for koha-passwd

Bug 17379: Add a man page for koha-passwd

Adding a manpage for the koha-passwd utility.

To test:
1) Run these commands and look at the formatted man page:
$xsltproc /usr/share/xml/docbook/stylesheet/docbook-xsl/manpages/docbook.xsl \
 debian/docs/koha-passwd.xml
2)$man -l koha-passwd.8

3) Make sure this test passes:  $prove -v xt/verify-debian-docbook.t

Signed-off-by: Mika Smith <mikasmith@catalyst.net.nz>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>